Function In Male Wistar Rats Research Articles

Activity of Alkaloid Extract of Carica papaya. Seeds on Reproductive Functions in Male Wistar Rats

ABSTRACTActivity of the alkaloid extract of Carica papaya. Linn seed on male reproductive physiology was investigated. Male rats were divided into two groups. Each group of 20 male rats was further divided into 4 subgroups of 5 rats. Each rat was treated with C. papaya. seed extract (10, 50, and 150 mg kg−1day−1) daily for 3 days for fecundity study, semen analysis, and testis histopathology, respectively. Twenty male rats treated with C. papaya. seed extract (10, 50, and 150 mg kg−1 day−1), abstained from sex for 7 days and divided into 4 groups, were mated with fertile female rats: another set of 30 male rats, divided into 4 groups, treated with the seed extract (10, 50, and 150 mg kg−1 day−1), respectively, was used for semen analysis and testis histopathology. The results showed that oral administration of C. papaya. seed extract prevented ovum fertilization, reduced sperm cell counts, revealed sperm cell degeneration, and induced testicular cell lesion. These observations led to the conclusion that C. papaya. seed extract oral administration could induce reversible male infertility and therefore could be used for pharmaceutical development of a male contraceptive.

The acute effects of norharman on cocaine self-administration and sensorimotor function in male Wistar rats

The purpose of the present study was to determine the acute effects of the β-carboline norharman on cocaine dependence. Male Wistar rats were allowed to self-administer cocaine for 3 h for seven sessions. A single injection of norharman (0.2–20 mg/kg, i.p.) was given 30 min before the onset of the seventh session. It was shown that norharman decreased the cocaine intake in a U-shaped manner with the dose of 10 mg/kg having the most potent effect. These results indicate that several receptor mechanisms mediate the effects of norharman. In addition, 15 min following the administration of norharman on session 7, motor and sensory skill tests were performed. Six naı̈ve animals were tested with the dose, which has the most pronounced effect on cocaine self-administration intake, in order to examine whether the observed effects were due to norharman or due to the combination of norharman and cocaine. It was observed that norharman in both the naı̈ve and cocaine-exposed animals significantly increased the response time in the somato-sensory orienting test. However, only in the naı̈ve animals a significant effect of norharman on the grasp reflex was observed.

The psoralens adversely affect reproductive function in male wistar rats

The psoralens occur naturally in produce and are widely used in skin therapy. Studies show that 5-methoxypsoralen and 8-methoxypsoralen reduced birth rates in rats. We determined the effect of psoralens on reproductive function in male rats. Male Wistar rats were dosed daily with 5-methoxypsoralen or 8-methoxypsoralen (75 or 150 mg/kg, p.o.), or vehicle control. Treated males had significantly smaller pituitary glands, fewer sperm per ejaculate, and fewer sperm in the vasa defferentia and epididymides than controls. Dosing significantly elevated levels of testosterone and increased relative testis weight, but did not directly affect testicular weight. Females bred to dosed males required more time to become pregnant, and these males required more breeding attempts. The findings demonstrate the importance of determining the potential risk for infertility and/or birth defects in humans who are exposed to therapeutic, dietary, or occupational psoralens.

Effects of chronic renal failure on hypothalamo-pituitary-testicular axis function and fertility in rats.

We evaluated the effects of chronic renal failure on hypothalamo-pituitary-testicular axis function in male Wistar rats. Chronic renal failure was induced by five-sixths nephrectomy in male rats. Seven to 10 weeks after the surgery, serum area and creatinine concentrations and hematocrits were evaluated, and human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) tests, and prolactin stimulating and suppression tests were performed. In addition, androgen-binding protein, epididymal sperm content, motility, and fertile potential were assessed. Basal serum testosterone concentrations and the response of testosterone to hCG were significantly lower in rats with chronic renal failure than in controls. Basal serum gonadotropin levels were elevated in rats with chronic renal failure, but the gonadotropin response to GnRH did not differ from that in controls. Serum prolactin levels responded appropriately to stimulation and suppression tests. Androgen-binding protein levels, epididymal sperm content, motility, and fertile potential were significantly lower in chronic rats. Chronic renal failure in rats interferes with endocrinologic mechanisms and testicular functions. Thus, uremic rats have a low fertile potential.

THYROID IODINE METABOLISM IN STREPTOZOTOCIN-DIABETIC RATS

ABSTRACT Experiments have been performed to assess the effect of diabetes on thyroid function in male Wistar rats. Diabetes was induced by a single streptozotocin injection. As compared to normals, the diabetic rats displayed: 1) decreased rate of stable iodine uptake by the gland, as measured with a double isotopic technique; 2) decreased in vitro iodide uptake by the thyroid; 3) decreased T/S [I-] ratio after acute treatment with propylthiouracil; and 4) alteration in the distribution of labelled iodoamino acids in the gland. Furthermore, diabetic rats maintained lower plasma TSH levels than normals, in spite of the fact that plasma PBI concentration was slightly but consistently lower in diabetic than in normals, and that the pituitary TSH content was not affected by the lack of normal insulin levels. Injections of TSH (5 U/100 g body weight/day) for 5 days, into diabetic rats caused a return of thyroid function toward normal. Insulin administration resulted in an increase of thyroid weight, an increase of thyroid function, and an increase of pituitary TSH secretion in diabetic rats after the daily injection of 1, 2 or 3 U/100 g body weight/day for 7 days. The decreased pituitary TSH secretion in diabetic rats might involve a disturbance in the feed-back relationship between the thyroid and the pituitary, although other mechanisms could be involved.