Sex-related Differences In Response Research Articles

Sex related difference in response to experimental pain in first year medical students

–Pain is complex multidimensional experience influenced by physical, psychological, and social factors. In recent years sex differences in responses to pain have received increased attention. Purpose of study was to determine sex differences in experimental pain response. For this study cold pressor test was used to exert experimental pain. 100 medical students (50 boys and 50 girls) participated in study. Subject was asked to submit his hand into container with ice water. Radial pulse was measured before and immediately after test to determine pulse reactivity. Pain threshold and tolerance were measured. Subject was asked to determine intensity of pain during test and rate on VAS. Data was statistically analysed using student t-test and Correlation Coefficient. Pain threshold and pain tolerance were significantly more in boys, Pain rating was significantly more in girls. Pain reactivity was significantly more in girls. In both sexes, baseline pulse showed positive relationship with pain threshold and pain tolerance and negative relationship with pain rating. Women typically displaying greater pain sensitivity than men, but mechanisms underlying differences remain unclear. Possible explanation suggests that men are more motivated to tolerate and suppress expressions of pain because masculine sex role, whereas feminine sex role encourages pain expression. Different pain perception might account for sex difference in pulse reactivity. Hormonal influences may play minor role.

Are there sex-related differences in responses to repetitive olfactory/trigeminal stimuli?

Sex differences in olfactory sensitivity have been reported since the late 1800's with women typically outperforming men on tests of odor detection, discrimination or identification. It is not known whether women adapt differently than men to olfactory and trigeminal stimuli. Seventeen healthy volunteers participated (9 female, 8 male, mean age 22 years) in the study. As established by an odor identification test (UPSIT, score > or =38) all subjects had normal olfactory function. Event-related potentials (ERPs) were recorded in response to olfactory (25% v/v phenyl ethyl alcohol) and trigeminal (44% v/v CO(2)) stimuli using a computer controlled olfactometer (flow 8 L/min; stimulus duration 200 ms). Stimuli were applied at four intervals (5, 10, 20, and 60 s). Amplitudes and latencies of ERP peaks P1, N1, and P2 were measured. Stimulus intensity also rated using visual analogue scales subjects. When compared to phenyl ethyl alcohol, the slightly more intense CO(2) produced larger amplitudes and shorter latencies. Both, ratings and ERP amplitudes P2 decreased with decreasing interval between stimuli. Responses to the trigeminal and olfactory stimuli changed similarly in relation to repetitive stimulation. Women had larger ERP amplitudes P2. No sex-related difference for ratings and ERP in relation to repeated stimulation amplitudes was observed. Although women exhibit larger ERP amplitudes to chemosensory stimuli compared to men, the present data indicate on both psychophysical and electrophysiological levels that there is no major difference between young, healthy men and women in relation to short-term adaptation to suprathreshold chemosensory stimulation.

Sex-related differences in response to aspirin in cardiovascular disease: an untested hypothesis

The Women's Health Study seemed to contradict evidence from randomized trials of aspirin by identifying a sex-related difference in response to aspirin in cardiovascular disease. In this Viewpoint Hennekens et al. discuss the findings and argue that concluding that there are sex-related differences in response to aspirin could be premature.

Sex-related differences in response of plasma lipids to simvastatin: The Saitama Postmenopausal Lipid Intervention study

The Saitama Postmenopausal Lipid Intervention Study was a multicenter, uncontrolled, collaborative study that investigated tolerability and sex-related differences in the response of serum lipids to simvastatin administered for 12 months in 122 postmenopausal women and 55 men with serum total cholesterol (TC) levels ≥220 mg/dL. With simvastatin treatment, TC and lowdensity lipoprotein cholesterol (LDL-C) levels decreased significantly at 1 month in both groups, and these decreased levels were maintained throughout treatment ( P < 0.001). A significant decrease in triglyceride (TG) levels was also observed in both groups ( P < 0.05). The mean percentage decreases in TC and LDL-C levels in women (20% and 28%, respectively) were significantly greater than those in men (15% and 20%, respectively) ( P < 0.001). Mean percentage changes in TC and LDL-C levels in subgroups defined by stratification for baseline TC and LDL-C levels were also greater in women. There were no sex-related differences in the percentage changes in TG or high-density cholesterol levels, although the changes were influenced by baseline levels. Although the median dose of simvastatin (milligrams per kilogram of body weight) in women was significantly higher than in men ( P < 0.001), the percentage changes in serum lipids were not correlated with the doses of simvastatin calibrated by body weight. Adverse reactions occurred in 8 men and 7 women, so there appeared to be no significant sexrelated difference. Eleven patients had abnormal laboratory values. Simvastatin therapy for 12 months is well tolerated and effective for both women and men with hypercholesterolemia. Sex-related differences occurred in the response to simvastatin therapy of serum lipids, especially TC and LDL-C, with greater changes in lipid levels occurring in women.

Comparison of Antinociceptive Effects Induced by Kappa Opioid Agonists in Male and Female Mice

A recent clinical report suggested that kappa opioids such as nalbuphine and butorphanol produced greater pain relief in women than in men. However, both compounds have been characterized as partial agonists with mixed mu/kappa opioid actions in animal studies. The aim of this study was to evaluate whether there is a sex difference in antinociception caused by nalbuphine and butorphanol as well as more selective kappa opioid agonists including U50,488 and Cl-977 in mice. In the acid-induced writhing assay, all compounds (U50,488: 1-10 mg/kg; Cl-977: 0.01-0.1 mg/kg; nalbuphine: 1-320 mg/kg; butorphanol: 0.032-0.32 mg/kg) dose-dependently inhibited writhing, but there were no sex-related differences found when comparing ED(50) values in male and female mice. In the warm water (48°C) tail withdrawal assay, U50,488 (10-100 mg/kg) and Cl-977 (0.1-3.2 mg/kg) also dose-dependently produced antinociception, although there were no sex-related differences observed. Nalbuphine (10-320 mg/kg) did not have antinociceptive effects under this condition. On the other hand, butorphanol (0.32-32 mg/kg) produced greater antinociception in male (50% MPE) than female mice (20% MPE). Further antagonist studies revealed that butorphanol is a mixed mu/kappa opioid with low efficacy. In summary, there were no sex-related differences in response to more selective kappa opioid agonists on antinociception in mice under these conditions.

Sex steroid regulation of thromboxane A 2 receptors in cultured rat aortic smooth muscle cells

Thromboxane A 2 (TXA 2) has been implicated as an important mediator of cardiovascular diseases, and male rat aortas are reported to be more sensitive to it than female aortas. The effects of sex steroids to regulate the expression of TXA 2 receptors in cultured male rat aortic smooth muscle cells (RASMC) were determined. TXA 2 receptor density (B max) and affinity (K d) were determined via radioligand binding studies with [ 125I]BOP, a TXA 2 receptor agonist. Testosterone increased Bmax in a concentration-dependent manner without any significant change in K d. Cycloheximide, actinomycin D, and the 5α-reduc-tase inhibitor L645,390 significantly ( P < 0.01) blocked the effect of testosterone. Dihydrotestosterone, the active metabolite of testosterone, increased B max and was more potent than testosterone. To determine if there is a sex-related difference in response to testosterone, its effect in cultured female RASMC was assessed. Testosterone increased B max in female RASMC but the increase was significantly ( P < 0.001) less than that seen in male RASMC. These results indicate that androgenic steroids regulate the expression of vascular TXA 2 receptors.

Do Sex-Related Differences in Response to Environmental Variation Influence the Sex-Ratio in the Dioecious Rumex acetosella?

Populations of the dioecious herb Rumex acetosella show variation in sex ratio along an old-field successional gradient in central France, where female-biased or 50:50 ratios occur in young populations and male-biased ratios occur in old populations. In order to test the hypothesis that differences in environmental sensitivity and/or reproductive biology account for sex related differences in habitat occupation of this species, two complementary experiments were performed. First, the environmental sensitivity (or reaction norms) of biomass allocation for male and female plants was examined over an experimental gradient of density and nutrients to test whether the sexes differ in habitat preference (...)

Long-Term Effects of Intraspecific and Interspecific Cross-Fostering on Two Species of Peromyscus

Reproduction, parental behavior, offspring survivorship, physical development, and growth were studied in Peromyscus that had been reared by foster parents of the same or a closely related species. Neither type of cross-fostering had any effect in P. leucopus. Interspecifically cross-fostered P. maniculatus exhibited severely depressed reproductive success, while intraspecific cross-fostering had little effect. Parental behavior was apparently unaffected by cross-fostering in both species. Sex-related differences in response to interspecific cross-fostering occurred in both species, with males more negatively affected than females.

Sex differences in central adrenoreceptor-mediated vasopressin response to hemorrhage

Hemorrhage-induced changes in the plasma vasopressin concentration and mean arterial blood pressure (MABP) were studied in conscious rats of both sexes with and without central alpha 1-adrenoreceptor blockade. Rats were subjected to two sequential hemorrhages (H1 and H2), each 0.8% of body weight after an intracerebroventricular injection of the alpha 1-adrenoreceptor antagonist corynanthine or of vehicle. H1 stimulated vasopressin secretion more in proestrous females than in males; there were no significant sex-related differences in responses to H2. Corynanthine pretreatment attenuated the vasopressin response to H2 in males, potentiated this response in proestrous females, but had no effect in estrous females. MABP decreased after H1 in all female groups and in corynanthine-pretreated males. After H2, all groups were hypotensive to the same extent. These data indicate that central alpha 1-adrenoreceptor-mediated pathways participate in vasopressin and blood pressure responses to hemorrhage, but their role is complex and is dependent on gender and on the phase of the estrous cycle.

Hormone- and dose schedule-dependent protection by HI-6 against soman and tabun poisoning

The protective ratio produced by HI-6 (with atropine) against soman and tabun poisoning in rats and guinea pigs was determined. The amount of protection afforded by HI-6 decreased with time following poisoning, prompting us to examine the effects of repeated doses of HI-6 (four additional) given over a 5-hr period. In addition, it was determined that HI-6 produced much better protection in female rats than male rats, which led to a study of the hormone dependence of this activity. When in addition to the first dose of HI-6 four additional doses were given over a 5-hr period, the protective ratio, defined as LD50 in treated animals/LD50 in untreated animals, in males against soman, increased from 4.2 to 7.8, and against tabun, from 2.5 to 6.6. A single dose of HI-6 produced a protective ratio in females of 10.5 against soman and 4.3 against tabun, whereas multiple doses increased these values to greater than 27 and 22, respectively. A regimen consisting of gonad removal and long-term treatment with a sex hormone of the opposite gender reversed the sex-related differences in response to the protective effects of HI-6. In addition a single injection of HI-6 (plus atropine), 1 min following either soman or tabun, produced good protective ratios in guinea pigs against both soman (between 4 and 5) and tabun (5.1); however, there was no apparent hormone-dependent effect similar to that obtained in rats. The results demonstrate unequivocal protective effects of HI-6 against tabun and a very dramatic hormone-dependent factor in its activity against either organophosphate. It can be inferred from the results that for maximal effectiveness against soman or tabun, maintenance of adequate blood/tissue levels of HI-6 is absolutely essential.

Site- and sex-related differences in adrenoreceptor status of human adipose tissue.

At equal degrees of absolute adiposity, the risk of associated morbidities such as hypertension, stroke, and ischemic heart disease is greater in individuals with predominantly abdominal as opposed to gluteal fat deposits (high waist to hip circumference ratio). We studied the in vitro status of adrenergic receptors controlling lipolysis (beta 1) and antilipolysis (alpha 2) in small fragments of adipose tissue from abdominal and gluteal sc depots of six obese women and six obese men. Lipolysis rate was measured by a double isotope technique which detects changes in the specific activity of fatty acids esterified to newly synthesized triglycerides. The lipolytic response to the beta-adrenergic agonist isoproterenol was significantly greater in abdominal compared to gluteal adipose tissue in both sexes. There was, however, no significant sex-related difference in response to isoproterenol within sites. When tissue from both sites was exposed to the mixed alpha/beta-adrenergic agonist norepinephrine there was a significantly greater lipolytic response in abdominal tissue. Within-site by sex analysis indicated no significant difference in the lipolytic response of gluteal tissue to norepinephrine, but a greater response of abdominal tissue in women. Given the apparently equal degree of beta responsiveness in abdominal tissue of both sexes, the norepinephrine data suggest that men have more abdominal alpha 2 receptor function (antilipolysis) than women. This difference may partially explain the greater tendency for men to accumulate adipose tissue in the abdominal region.

The mutagenic potential of hyperthermia and fever in mice

The cytogenetic effects of hyperthermia resulting from climatic influences as well as from infections were studied. Whole-body exposure of NMRI mice to an elevated environmental temperature induced a high frequency of micronucleated polychromatic erythrocytes in bone marrow. Hyperthermia at high relative humidity was more effective in increasing body temperature and cytogenetic damage than at low RH. A sex-related difference in response to heat stress was observed. Hyperthermia on pregnant mice induced a significant increase in the incidence of micronucleated PEs in fetal blood cells. Parenteral administration of bacterial endotoxin, lipopolysaccharides, induced either hypothermia or hyperthermia. However, LPS-induced hypothermia as well as fever does not so far appear to produce cytogenetic damage.

Early changes in mitochondrial monoamine oxidase activity of rat liver during 2-acetylaminofluorene feeding

The activities of mitochondrial type A and B monoamine oxidase were determined in the liver of rats fed a diet containing 2-acetylaminofluorene (AAF). Three days after the initiation of AAF-feeding, there was a significant decrease of type B monoamine oxidase activity without affect on type A enzyme. The decreased activity of type B monoamine oxidase, which reached a minimum after three weeks, was sustained for as long as AAF-feeding was continued. Sex-related difference in response to AAF was seen in the rat with respect to the onset and the intensity of the decreased type B monoamine oxidase activity, male rats being more sensitive to the carcinogen than female rats. In contrast to the in vivo effect, AAF showed a potent inhibitory effect on type A monoamine oxidase, rather than on type B enzyme, when added in vitro. The p I 50 values were estimated to be 7.5 against type A monoamine oxidase and 4.1 against type B enzyme, respectively. The in vitro inhibition of both types of monoamine oxidase by AAF was competitive. The K i values for AAF were calculated to be 9.51 · 10 −9 M for type A monoamine oxidase and 1.30 · 10 −5 M for type B enzyme, respectively. In accordance with the potent inhibitory effect of AAF on type A monoamine oxidase in vitro, a single administration of the carcinogen, at a dose of 50 mg/kg, resulted in a marked and temporal decrease of the enzyme activity in the mitochondria of male rat liver. Recovery of the decreased type B monoamine oxidase activity was slow, and the enzyme activity did not return to control levels, even if rats were fed the basal diet for 2 or 4 weeks after the cessation of AAF-feeding.

Free erythrocyte protoporphyrin (FEP) in a general population, workers exposed to low-level lead, and organic-solvent workers

The present study deals with a response of free erythrocyte protoporphyrin (FEP) to decreasing hemoglobin (Hb) concentration, low-level lead exposure, and organic-solvent exposure. FEP and Hb levels were determined for 1079 nonexposed persons (191 males and 888 females), 455 workers exposed to low-level lead (193 males and 262 females), and 312 employees working with various organic solvents (228 males and 84 females). The mean FEP in relation to Hb and sex was calculated for the three study groups. The major findings concern a sex-related difference in the response of FEP: women showed a more intense and earlier response to decreasing Hb and lead exposure than men. A significantly higher mean FEP at various normal Hb levels in the female lead workers than the male lead workers seemed to eliminate the possibility that a relative iron deficiency in women may play a role in the sex-related difference in the FEP response to lead. Exposure to organic solvents showed no effect on the heme biosynthesis as reflected by FEP.

Sex differences in the antithrombotic effects of aspirin

Aspirin inhibits platelet function by acetylating platelet cyclooxygenase. Recent clinical trials indicate that aspirin is a promising antithrombotic agent against both venous and arterial thrombosis, but somewhat surprisingly this protective effect appears to be limited to males. To examine the potential sex-related differences in response to aspirin, we developed an animal model for quantitating fibrin accretion into an injury-induced thrombus and used it to study the effects of aspirin on thrombus size in male and female rabbits. Platelet prostaglandin synthesis was estimated by assay of platelet malondialdehyde and was significantly decreased in both male and female rabbits following treatment with 10 mg/kg aspirin (p less than 0.001). This inhibitory effect was not different for platelets from male and female rabbits. Thrombus size was significantly decreased in aspirin- treated male rabbits when compared to controls (p less than 0.05), but this aspirin effect was not apparent in female rabbits or rabbits of either sex treated with 10 mg/kg sodium salicylate. These findings support the results of clinical trials that were obtained by retrospective subgroup analysis. The reason for the sex difference is not known, but the findings raise an important issue in relationship to this mechanism of the antithrombotic effect of aspirin.

Sex-Related Differences in Response to Practice on a Visual-Spatial Test and Generalization to a Related Test

93 first graders (mean age 6.5 years) were given a pretest and posttest on half of the items from the Children's Embedded Figures Test. Half of the children were randomly assigned to a training condition and received a brief training procedure on visual-spatial disembedding prior to the administration of the posttest. Children in the control condition received no training. The performance of girls improved significantly more from pretest to posttest than the performance of boys. Boys and girls showed similar beneficial effects of training in addition to the benefit of direct practice. The tendency that was observed for boys to perform higher than girls on the pretest, p less than .10, was not evident on the posttest. Scores on the pretest predicted scores on a different measure of visual-spatial ability only for children in the control group. The results are interpreted in terms of current theories of sex differences in visual-spatial perception.

Sex differences in response to dietary carbohydrates

In order to determine the sex-related differences in responses to dietary carbohydrates male and female baboons were administered glucose and fructose iv. To determine whether these differences are due to metabolic or gastrointestinal factors subsequent levels of sugars and triglyceride in the serum were measured. The males were observed to show a faster rate of disappearance of the fructose from the serum than the mature females. The rate in the immature females was more similar to that of the mature males. No such differences were found with glucose. Administration of radioactive fructose showed that the specific activity of the serum triglycerides was higher in the males than in the females. Administration of gestagen hormones to other animals suggested an influence of these hormones on the lipid metabolism. Evidence is not yet considered conclusive.

Olfactory perception thresholds for citral utilizing a new type olfactorium.

ARTICLESOlfactory Perception Thresholds for Citral Utilizing a New Type OlfactoriumRobert A. Schneider, and Stewart WolfRobert A. Schneider, and Stewart WolfPublished Online:01 Nov 1955https://doi.org/10.1152/jappl.1955.8.3.337MoreSectionsPDF (979 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByOlfactory perception and integrationMetabolic status and olfactory functionAre there sex-related differences in responses to repetitive olfactory/trigeminal stimuli?11 November 2008 | European Archives of Oto-Rhino-Laryngology, Vol. 266, No. 8Lower olfactory threshold during the ovulatory phase of the menstrual cycleBiological Psychology, Vol. 63, No. 3Olfaction and Taste15 April 2003Brain activation during odor perception in males and femalesNeuroreport, Vol. 12, No. 9Diurnal Variations in Olfactory Sensitivity and the Relationship to Food Intake21 November 2016 | Perceptual and Motor Skills, Vol. 78, No. 1Research equipment for sensory air quality studies of nonindustrial environmentsEnvironment International, Vol. 12, No. 1-4Sex differences in odor identification ability: A cross-cultural analysisNeuropsychologia, Vol. 23, No. 5Gonadal hormones and sensory functionNeuroscience & Biobehavioral Reviews, Vol. 7, No. 1Prepyriform seizure thresholds during the estrous cycle in female ratsExperimental Neurology, Vol. 42, No. 2Design of an “odor perception and objectionability threshold” test facilityAtmospheric Environment (1967), Vol. 2, No. 2 More from this issue > Volume 8Issue 3November 1955Pages 337-342 https://doi.org/10.1152/jappl.1955.8.3.337PubMed13271265History Published online 1 November 1955 Published in print 1 November 1955 Metrics