Significant Elevation Of Plasma Research Articles

Purslane and Garden Cress Seeds as Source of Unconventional Edible Oils for Prevention of Hyperlipidemia.

Hyperlipidemia (HLP) is a leading cause for cardiovascular disease and atherosclerosis. Insufficient physical activity and unhealthy diet plays an important role in the progression of HLP. The present study was conducted to investigate the protective effect of 2 unconventional edible oils (purslane and garden cress) on hyperlipidemia. Diet high in fat and cholesterol was used as inducer of hyperlipidemia in rats for 5 weeks. Plasma and hepatic lipid profile were assessed. Plasma levels of malondialdehyde (MDA) as lipid peroxidation indicator was determined. Liver transaminases (AST and ALT) as liver function indicator and kidney function (creatinine and urea) were evaluated. Results clarified significant elevation in plasma and liver lipid profiles, MDA, liver enzymes (AST and ALT) and kidney function (creatinine and urea) in hyperlipidemic control compared to normal control. Supplementation with purslane and garden cress seeds oils either in diet or oral showed significant improvement in all the studied parameters. Purslane and garden cress oils investigated in the current study produced significant reduction and elevation in bad and good cholesterol, respectively in plasma. Also both oils reduced hepatic lipid accumulation effectively in hyperlipidemia model in rats. Oils administration reduced plasma malondialdehyde and improves liver and kidney functions.

Preparation and Evaluation of Functional Foods for Prevention of Non-alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) is a public health problem presenting one of the most important common forms of liver diseases worldwide. This study was carried out to investigate the protective effect of two functional foods in form of bread containing purslane seeds meal and garden cress seeds against NAFLD. High fat and high cholesterol diet were used for induction of NAFLD in rats for 6 weeks. Plasma lipid profile (total cholesterol, triglycerides, high density lipoprotein-cholesterol and low-density lipoprotein-cholesterol, hepatic lipid profile (total fat, cholesterol, triglycerides), malondialdehyde (MDA), as well as liver (AST, ALT, total and direct bilirubin) and kidney (creatinine and urea) functions were assessed. Histological examination of liver tissue was carried out. Results revealed that significant elevation in plasma and liver lipid profiles, MDA, liver enzymes (AST and ALT), bilirubin (total and direct) and kidney function (creatinine and urea) were observed in NAFLD control compared to normal control. Feeding rats on diet containing functional food I and II (purslane and garden cress bread, respectively) showed significant improvement in all the studied parameters with remarkable effect regards to functional food I (purslane bread). Purslane bread and garden cress bread as functional foods prepared in the present study prevent weight gain, improve plasma lipid profile and prevent hepatic lipid accumulation effectively in NAFLD model in rats. Also decreased lipid peroxidation, improve liver and kidney functions and possess hypoglycemic effect. Purslane bread was superior in the prevention of hepatic lipid accumulation.

Elevated plasma and cerebrospinal fluid interleukin-1 beta and tumor necrosis factor-alpha concentration and combined outcome of death or abnormal neuroimaging in preterm neonates with early-onset clinical sepsis.

Prematurity and sepsis are the major contributors of neonatal mortality and neurodevelopmental sequelae. The present study was conducted to measure the plasma and cerebrospinal fluid (CSF) concentration of interleukin (IL)-1β and tumor necrotic factor (TNF)-α in preterm neonates with early-onset clinical sepsis (EOCS), and to find out their association with combined outcome of death or abnormal neuroimaging. Thirty-two preterm (⩽34 weeks) neonates with EOCS and 32 gestational age-matched, healthy neonates served as cases and controls, respectively. Samples were collected soon after birth. Neonates were followed up clinically and by serial cranial ultrasonography (CUS) until discharge and subsequently by magnetic resonance imaging (MRI) of brain until 1 year. Developmental screening was done by Denver Developmental Screening test-II. In EOCS group, no neonate had any clinical/microbiological evidence of meningitis. Blood culture was positive in 17 (53%). CUS was abnormal in 12 (37%) (intracranial hemorrhage-11, periventricular leukomalacia-1). Ten (31%) neonates expired. Significant elevation of plasma and CSF IL-1β and TNF-α was observed in the EOCS group. On follow-up, seven (22%) neonates showed evidence of white matter damage in MRI, two of them had developmental delay and microcephaly. Plasma and CSF IL-1β and TNF-α concentration were significantly elevated in deceased neonates and those with abnormal neuroimaging. Both biomarkers demonstrated high predictive accuracy for poor outcome in receiver-operating curve analysis. Elevation of plasma and CSF IL-1β and TNF-α is associated with an increase in the combined outcome of death or abnormal neuroimaging in preterm neonates with EOCS in the absence of clinical/microbiological evidence of meningitis with high predictive accuracy.

Liver X Receptor (LXR) partial agonists: Biaryl pyrazoles and imidazoles displaying a preference for LXRβ

A series of biaryl pyrazole and imidazole Liver X Receptor (LXR) partial agonists has been synthesized displaying LXRβ selectivity. The LXRβ selective partial agonist 18 was identified with potent induction of ATP binding transporters ABCA1 and ABCG1 in human whole blood (EC50=1.2μM, 55% efficacy). In mice 18 displayed peripheral induction of ABCA1 at 3 and 10mpk doses with no significant elevation of plasma or hepatic triglycerides at these doses, showing an improved profile compared to a full pan-agonist.

Inhibition of P‐glycoprotein enhances transport of imipramine across the blood–brain barrier: microdialysis studies in conscious freely moving rats

Recent studies indicate that efflux of antidepressants by the multidrug resistance transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) may contribute to treatment-resistant depression (TRD) by limiting intracerebral antidepressant concentrations. In addition, clinical experience shows that adjunctive treatment with the P-gp inhibitor verapamil may improve the clinical outcome in TRD. Therefore, the present study aimed to investigate the effect of P-gp inhibition on the transport of the tricyclic antidepressant imipramine and its active metabolite desipramine across the BBB. Intracerebral microdialysis in rats was used to monitor brain levels of imipramine and desipramine following i.v. imipramine administration, with or without pretreatment with one of the P-gp inhibitors verapamil or cyclosporin A (CsA). Plasma drug levels were also determined at regular intervals. Pretreatment with either verapamil or CsA resulted in significant increases in imipramine concentrations in the microdialysis samples, without altering imipramine plasma pharmacokinetics. Furthermore, pretreatment with verapamil, but not CsA, led to a significant elevation in plasma and brain levels of desipramine. The present study demonstrated that P-gp inhibition enhanced the intracerebral concentration of imipramine , thus supporting the hypothesis that P-gp activity restricts brain levels of certain antidepressants, including imipramine. These findings may help to explain reports of a beneficial response to adjunctive therapy with verapamil in TRD.

Inorganic nitrate ingestion improves vascular compliance but does not alter flow-mediated dilatation in healthy volunteers

Ingestion of inorganic nitrate elevates blood and tissue levels of nitrite via bioconversion in the entero-salivary circulation. Nitrite is converted to NO in the circulation, and it is this phenomenon that is thought to underlie the beneficial effects of inorganic nitrate in humans. Our previous studies have demonstrated that oral ingestion of inorganic nitrate decreases blood pressure and inhibits the transient endothelial dysfunction caused by ischaemia–reperfusion injury in healthy volunteers. However, whether inorganic nitrate might improve endothelial function per se in the absence of a pathogenic stimulus and whether this might contribute to the blood pressure lowering effects is yet unknown. We conducted a randomised, double-blind, crossover study in 14 healthy volunteers to determine the effects of oral inorganic nitrate (8mmol KNO3) vs. placebo (8mmol KCl) on endothelial function, measured by flow-mediated dilatation (FMD) of the brachial artery, prior to and 3h following capsule ingestion. In addition, blood pressure (BP) was measured and aortic pulse wave velocity (aPWV) determined. Finally, blood, saliva and urine samples were collected for chemiluminescence analysis of [nitrite] and [nitrate] prior to and 3h following interventions. Inorganic nitrate supplementation had no effect on endothelial function in healthy volunteers (6.9±1.1% pre- to 7.1±1.1% post-KNO3). Despite this, there was a significant elevation of plasma [nitrite] (0.4±0.1μM pre- to 0.7±0.2μM post-KNO3, p<0.001). In addition these changes in [nitrite] were associated with a decrease in systolic BP (116.9±3.8mm Hg pre- vs. 112.1±3.4mm Hg post-KNO3, p<0.05) and aPWV (6.5±0.1m/s pre- to 6.2±0.1 post-KNO3, p<0.01). In contrast KCl capsules had no effect on any of the parameters measured. These findings demonstrate that although inorganic nitrate ingestion does not alter endothelial function per se, it does appear to improve blood flow, in combination with a reduction in blood pressure. It is likely that these changes are due to the intra-vascular production of NO.

Protective effect of grape seed proanthocyanidin extract against oxidative stress induced by cisplatin in rats

Cisplatin is one of the most potent chemotherapeutic antitumor drugs. Oxidative stress has been proven to be involved in cisplatin-induced toxicity. Therefore, the present study was undertaken to examine the antioxidant potential of grape seed proanthocyanidin extract (GSPE) against the toxicity of cisplatin in male rats. Cisplatin treated animals revealed a significant elevation in plasma, heart, kidney and liver thiobarbituric acid reactive substances (TBARS), while the activities of antioxidant enzymes (GST, SOD, CAT and GSH-Px, and the levels of glutathione (GSH) were decreased. Aspartate and alanine transaminases (AST and ALT), creatine kinase and lactate dehydrogenase were significantly increased in plasma, while liver AST and ALT were significantly decreased. Cisplatin significantly increased the levels of plasma total lipid, cholesterol, urea and creatinine, and the relative weight of kidney. On the other hand, plasma total protein and albumin, and body weight were significantly decreased. GSPE reduced cisplatin-induced the levels of TBARS in plasma, heart, kidney and liver, TL, cholesterol, urea and creatinine, and liver AST and ALT. Moreover, it ameliorated cisplatin-induced decrease in the activities of antioxidant enzymes, and GSH, total protein and albumin. Therefore, the present results revealed that GSPE exerts a protective effect by antagonizing cisplatin toxicity.

Effect of Plumbago zeylanica L. on Blood Glucose and Plasma Antioxidant Status in STZ Diabetic Rats

The study was undertaken to evaluate the antioxidant potential of Plumbago zeylanica L. in streptozotocin (STZ) diabetic rats. The ethanolic extract of root of P. zeylanica L. at doses of 100 mg, 200 mg/kg p.o. for 21 days resulted in significant reduction in plasma TBARS and a significant elevation in plasma reduced glutathione (GSH), ascorbic acid. It is concluded that these results suggest that the ethanolic extract of root of P. zeylanica L. possess a strong antioxidant effect in diabetic rats.

Effect of Red Hogweed (Boerhavia diffusa L.) on Plasma Antioxidants in Alloxan-Induced Diabetes

ABSTRACT The present study was designed to evaluate the antioxidant activity of an aqueous Boerhavia diffusa leaf extract (BLEt) (200 mg/kg) in rats with alloxan-induced diabetes mellitus. Administration of BLEt for four weeks resulted in a significant reduction in plasma thio-barbituric acid reactive substances (TBARS), lipid peroxides, cerulo-plasmin, and α-tocopherol and a significant elevation in plasma of reduced glutathione and vitamin C in the diabetic rats. A comparison between the action of BLEt and antidiabetic drug glibenclamide (600 μg/kg) indicated the effect of BLEt was more prominent than glibenclamide.

Hypoglycaemic effect of water extracts of Aegle marmelos fruits in streptozotocin diabetic rats

Aegle marmelos Corr. (Rutaceae) is widely used in Indian Ayurvedic medicine for the treatment of diabetes mellitus. The hypoglycaemic effect of the water extract of the fruits of Aegle marmelos was examined in streptozotocin-induced diabetic Wistar rats. Oral administration of the water extract (125 and 250 mg kg −1) twice a day for 4 weeks resulted in significant reductions in blood glucose, plasma thiobarbituric acid reactive substances, hydroperoxides, ceruloplasmin and α-tocopherol and a significant elevation in plasma reduced glutathione and Vitamin C in diabetic rats. The effect of the extract at a dose of 250 mg kg −1 was more effective than glibenclamide in restoring the values of these parameters. The results of this study clearly shows the hypoglycaemic activity of the fruit extract.

Relationship between plasma D(-)-lactate and intestinal damage after severe injuries in rats.

To explore the kinetic changes in plasma D(-)-lactate and lipopolysaccharide (LPS) levels, and investigate whether D(-)-lactate could be used as a marker of intestinal injury in rats following gut ischemia/reperfusion, burn, and acute necrotizing pancreatitis (ANP). Three models were developed in rats: (1)gut ischemia/reperfusion obtained by one hour of superior mesenteric artery occlusion followed by reperfusion; (2)severe burn injury created by 30% of total body surface area (TBSA) full-thickness scald burn; and (3)ANP induced by continuous inverse infusion of sodium taurocholate and trypsin into main pancreatic duct. Plasma levels of D(-)-lactate in systemic circulation and LPS in portal circulation were measured by enzymatic-spectrophotometric method and limulus amebocyte lysate (LAL) test kit, respectively. Tissue samples of intestine were taken for histological analysis. One hour gut ischemia followed by reperfusion injuries resulted in a significant elevation in plasma D(-)-lactate and LPS levels, and there was a significant correlation between the plasma D(-)-lactate and LPS (r = 0.719, P<0.05). The plasma concentrations of D(-)-lactate and LPS increased significantly at 6h postburn, and there was also a remarkable correlation between them (r=0.877 P<0.01). D(-)-lactate and LPS levels elevated significantly at 2h after ANP, with a similar significant correlation between the two levels (r = 0.798, P < 0.01). The desquamation of intestine villi and infiltration of inflammatory cells in the lamina propria were observed in all groups. The changes of plasma D(-)-lactate levels in systemic blood paralleled with LPS levels in the portal vein blood. The measurement of plasma D(-)-lactate level may be a useful marker to assess the intestinal injury and to monitor an increase of intestinal permeability and endotoxemia following severe injuries in early stage.

Dietary Supplementation of a Natural Isomer Mixture of Beta-Carotene Inhibits Oxidation of LDL Derived from Patients with Diabetes mellitus

Background: Accelerated atherosclerosis is common in patients with diabetes mellitus which may be linked to increased lipid peroxidation. Therefore, we compared the oxidation of LDL derived from patients with diabetes to normoglycemic controls and followed-up the effect of dietary β-carotene supplementation on LDL oxidation. Methods: Twenty patients with long-standing non-insulin-dependent diabetes mellitus were studied in comparison with age- and sex-matched control subjects. Dunaliella bardawil-derived β-carotene was supplemented to the patients for 3 weeks, 60 mg daily dose. LDL oxidation was analyzed by measuring malondialdehyde (MDA), lipid peroxides (PD), and conjugated dienes (CD) generation in response to CuSO₄-induced oxidation. LDL lipid composition and the LDL associated vitamins A, E and carotenoids were also measured. Results: LDL susceptibility to oxidation by CuSO₄ was increased in the patients by 40% with a 35% shorter lag time required for the initiation of LDL oxidation, i.e. 56 ± 6 min in patients vs. 85 ± 9 min in controls (p <0.01). Patients showed increased cholesterol/phospholipid and polyunsaturated/saturated ratios, as well as reduced content of LDL associated vitamins. Upon β-carotene supplementation, there was a significant elevation in plasma and in LDL all-trans β-carotene [from 0.296 ± 0.020 to 0.968 ± 0.133 μg/mg LDL protein (p < 0.01)] paralleled by a significant reduction in LDL susceptibility to oxidation, as exhibited by increased lag time up to 115 ± 10 min (p < 0.01) and reduction in MDA and PD generation (by 25 and 40%), respectively (p < 0.01). Conclusions: Increased susceptibility to oxidation of LDL derived from patients with diabetes mellitus is associated with abnormal LDL lipid composition and antioxidant content. Natural β-carotene dietary supplementation normalizes the enhanced LDL oxidation and consequently may be of importance in delaying accelerated development of atherosclerosis in these patients.

Effect of Syzigium cumini in Plasma Antioxidants on Alloxan-Induced Diabetes in Rats.

We undertook the present study to evaluate the antioxidant activity of an aqueous extract of the seeds of Syzigium cumini, an indigenous plant present in different parts of India, South-East Asia and Eastern Africa, toward experimental diabetes. Administration of the extract for 6 weeks resulted in significant reductions in plasma lipid peroxide, ceruloplasmin and α-tocopherol and a significant elevation in plasma reduced glutathione and vitamin C in alloxan diabetic rats. Insulin restored all the parameters to their normal values. The seed extract was also more effective than glibenclamide in restoring the values of these parameters.

Enoxaparin (Clexane®, Lovenox®), a low molecular weight heparin, enhances t-PA-induced coronary thrombus lysis in anesthetized dogs without inducing hypocoagulability

An occlusive coronary thrombus was obtained in barbiturate anesthetized dogs within 60 min following the angiographic placement of a copper coil into the left descending coronary artery. This thrombus persisted for the 60 min experimental period, within which the effects of i.v. t-PA (10 μg/kg/min for 30 min) alone or combined with i.v. heparin (0.63 mg/kg twice) or enoxaparin (1.5 mg/kg twice) were evaluated. t-PA alone achieved recanalization for 20 min in only 2 out of the 5 dogs studied. Combination of t-PA with either heparin or enoxaparin produced this effect in all the 5 dogs studied. In dogs treated with t-PA associated to either heparin or enoxaparin, the thrombus weight was smaller (decreases of 34% and 44% respectively) than in animals given t-PA alone. The plasma amidolytic activity, expressed as t-PA activity, was greater 15 min after the beginning of t-PA infusion, in dogs pretreated with either heparin or enoxaparin than in animals given t-PA alone. Conversely, during t-PA infusion, the apparent t-PA inhibitor and antiplasmin activities were no longer measurable in the plasma, but reappeared 10 min after the end of t-PA infusion. Plasma coagulation time was not modified by t-PA, but was slightly prolonged (2-fold) by enoxaparin and markedly (7-fold) by heparin on initiation of t-PA infusion. Plasma anti-Ila activity was 3-fold higher in dogs pretreated with heparin as opposed to enoxaparin. On the contrary, both compounds increased similarly plasma anti-Xa activity. In conclusion, these results indicate that enoxaparin, like heparin, enhances the thrombolytic effects of t-PA. This favourable effect occurs independently of a plasma hypocoagulable state, which was clearly produced by heparin but not enoxaparin. Its mechanism may be the significant elevation of plasma t-PA activity produced by both heparin and enoxaparin during t-PA infusion.

PERINATAL ASPHYXIA AND PLASMA β ENDORPHINS

In an attempt to determine whether plasma β endorphin (β-ED) concentrations correlate with perinatal asphyxia, measurements were made in three groups of term infants. Group 1 (control) consisted of eight infants with a mean (± SE) gestation of 38.6 ± 0.4 weeks, a mean birthweight of 3420 ± 150 g, and a mean postnatal age of 1.4 ± 0.7 days. Group 2 consisted of ten infants with perinatal asphyxia with a mean gestational age, birthweight and postnatal age of 40.1 ± 0.5 weeks, 3310 ± 80 g and 3.9 ± 1.1 days, and Group 3 included six infants with a mean gestational age, birthweight and postnatal age of 40.4 ± 1 week, 3650 ± 310 g, and 2.8 ± 1 day, respectively. Group 2 and 3 infants suffered clinical and neurological evidence of hypoxicischemic brain injury, however, infants in Group 2 suffered meconium aspiration, persistent fetal circulation with on-going hypoxemia as measured by transcutaneous or umbilical arterial oxygen monitoring. Group 3 infants were normoxemic after resuscitation. The mean (± SE) plasma β-ED concentrations were 19 ± 2.7 pg/ml, 103 ± 35.7 pg/ml and 25 ± 4.5 pg/ml in Groups 1, 2 and 3, respectively. A significant elevation of plasma β-ED concentration was observed in Group 2 when compared to Groups 1 and 3. The association of increased plasma β-ED concentration in infants with hypoxic-ischemic encephalopathy associated with on-going hypoxemia suggests that hypoxemia may act as a strong stimulus for plasma β-ED release in term infants.

Increased blood-brain transport of tryptophan after portacaval anastomoses in germ-free rats

Portal-systemic shunting in rats results in altered plasma concentrations of the large neutral amino acids (NAA), and increased blood-brain barrier NAA transport. Bacterial ammonia production in the bowel, especially the colon, is thought to play a major role in the etiology of portal-systemic encephalopathy (PSE). In order to isolate the role of bacteria in PSE, plasma and brain amino acids and ammonia (NH 3) were studied in germ-free (GF) rats with portacaval shunts (PCS). Germ-free rats underwent end-to-side portacaval shunt or sham operation under germ-free conditions and were kept in a germ-free isolator under careful bacteriologic control. Similar operations were carried out on conventional animals. Two weeks post-operatively blood-brain transport of the neutral amino acid tryptophan was studied and the animals sacrificed. Plasma NH 3 rose after PCS both in GF and in conventional rats. In germ-free and conventional rats with PCS, there was a significant elevation in plasma of the aromatic amino acids and decreased concentrations of the branched-chain amino acids. In the brain, both groups had elevated aromatic amino acids, while the branched-chain amino acids remained normal. The blood-brain transport of tryptophan was elevated in portacaval shunted rats, whether germ-free or conventional. These studies suggest the elevated plasma levels of ammonia and disturbances in plasma and brain amino acids seen after portacaval shunt are not dependent on the presence of gut bacteria.

Role of the hypophysis in the regulation of vitamin D metabolism

Hypophysectomy of animals given maintenance levels of vitamin D and adequate levels of dietary calcium and phosphorus brings about a marked reduction in plasma 1,25-dihydroxyvitamin D 3 levels and a significant elevation in plasma 24,25-dihydroxyvitamin D 3 levels. The hypophysectomy, as expected, results in reduced growth and lowered plasma levels of inorganic phosphorus. The injection of growth hormone markedly increases plasma levels of 1,25-dihydroxyvitamin D 3 in hypophysectomized animals while bringing about a reduction in 24,25dihydroxyvitamin D 3 levels. These results support the idea that the hypophysis plays a role in the regulation of vitamin D metabolism and that growth hormone either directly or indirectly is one of the hypophyseal factors bringing about this regulation.

Ultra-violet irradiation and 25-hydroxy-vitamin D levels in sick old people.

Twelve elderly patients in a rehabilitation ward were given a four-week course of ultra-violet irradiation from a Vitalux lamp. They were compared with 12 controls selected from the same ward. Treatment produced a significant elevation in plasma 25-hydroxy-vitamin D (25OHD) by the end of the second week and concentrations continued to rise over the four-week period. Subject showing the greatest response were those starting with the lowest levels of plasma 25OHD. The findings suggest that ultra-violet irradiation is an effective means of treating vitamin D deficiency in old age and that patients with the greatest degree of deficiency show the greatest response.

Studies on testosterone-17β-glucosiduronate in human plasma

A specific radioimmunoassay (RIA) for the determination of testosterone-17β-glucosiduronate (TG) in human plasma is described. A sensitivity of 25 pg was obtained in the standard curve with an intra-assay coefficient of variation (CV) of 8.5% and an inter-assay CV of 12.5%. Plasma TG concentrations were found as follows (mean ± S.D., ng/ml): Normal males 2.1 ± 0.45 ( n = 20); normal females 0.47 ± 0.18 ( n = 17); hirsute females 1.36 ± 0.68 ( n = 14); hypogonadic males 1.08 ± 0.3 ( n = 10). TG concentration in the testicular vein of a normal male was 1.91 ng/ml, 30 min after 5000 IU HCG iv 3.0 ng/ml. The infusion of 2mg of TG for 2 h to normal men induced a 16-fotd increase in plasma TG levels, reaching a steady state after 1 h. Plasma concentrations of unconjugated testosterone (T) and 5α-dihydrotestosterone (DHT) estimated simultaneously were not altered. Intravenous infusions of 1000 IU HCG caused a significant elevation of plasma T but no change in plasma TG levels.

Thyroid and gonadal function in hypophysectomized hagfish, Eptatretus stouti

Use of a surgical hypophysectomy procedure which produces complete removal of the neuro- and adenohypophysis, and which permits survival of a large proportion of treated hagfish, has made possible an extensive study of the tropic relations of the hagfish pituitary gland. As long as 7 months after complete hypophysectomy, although some abnormalities were found in both testes and ovaries, gametogenesis still appeared to go to completion, indicating independence of the hagfish gonad from hypophysial gonadotropic control. There was similar lack of morphological evidence for thyrotropic control in these animals. Analysis of plasma levels of testosterone, estradiol and thyroxine also revealed no evidence of relation to presence of the pituitary gland. Subcutaneous multiple implants of pituitary glands did not affect plasma levels of the sex steroids, but were associated with a significant elevation of plasma T 4, suggesting a thyrotropic function of the implants. A negative correlation of plasma testosterone and body length in female hagfish was found, and implications of this finding are discussed. It was concluded that no clear evidence for hypophysial gonadotropic or thyrotropic function can be found in hypophysectomy experiments in hagfish. Evidence of thyrotropic activity by multiple subcutaneous transplants requires further study.