Prenatal morphine exposure alters estrogen regulation of κ receptors in the cortex and POA of adult female rats but has no effects on these receptors in adult male rats

SUMMARY The effect of progesterone on the rate of sebum secretion was examined in intact and gonadectomized rats. In intact, adult, male rats, progesterone administered for 3 weeks decreased sebum secretion; after castration of adult males, progesterone increased sebum secretion and an even greater response occurred in males castrated at 21 days of age. In intact, adult, female rats progesterone slightly increased sebum production. As in the male, the response was affected by the time of gonadectomy, a greater response occurring after spaying at 21 days compared with 10 weeks of age. Thus, the response to progesterone in the adult rat differs in intact males and females and is affected by changes in the endocrine environment induced by gonadectomy, especially near the time of puberty.

Download Full-text

A Quantitative Immunocytochemical Study of the Luteinizing Hormone and Follicle-Stimulating Hormone Cells in the Adenohypophysis of Adult Male Rats and Adult Female Rats throughout the Estrous Cycle*

Endocrinology ◽

10.1210/endo-113-3-970 ◽

1983 ◽

Vol 113 (3) ◽

pp. 970-984 ◽

Cited By ~ 37

Author(s):

M. O. DADA ◽

G. T. CAMPBELL ◽

C. A. BLAKE

Keyword(s):

Luteinizing Hormone ◽

Estrous Cycle ◽

Adult Female ◽

Adult Male ◽

Follicle Stimulating Hormone ◽

Female Rats ◽

Male Rats ◽

Immunocytochemical Study ◽

Stimulating Hormone

Download Full-text

Endocrine regulation of sex differences in hepatic histidase activity

Biochemical Journal ◽

10.1042/bj2310785 ◽

1985 ◽

Vol 231 (3) ◽

pp. 785-787 ◽

Cited By ~ 1

Author(s):

C A Lamartiniere

Keyword(s):

Sex Differences ◽

Adult Female ◽

Adult Male ◽

Pituitary Hormones ◽

Female Rats ◽

Male Rats ◽

Endocrine Regulation ◽

Pituitary Glands

Hepatic histidase activity in adult female rats is twice that in adult male rats. Hypophysectomy and thyroidectomy result in a significant increase in hepatic histidase activities in males, but not in females. This effect on histidase is reversed by the exogenous administration of tri-iodothyronine, but not by ectopic pituitary glands or purified pituitary hormones.

Download Full-text

Effects of Age and Sex on the Healing of Acetic-Acid Induced Ulcerative Colitis in Adult Wistar Rats

Asian Journal of Medicine and Health ◽

10.9734/ajmah/2021/v19i930367 ◽

2021 ◽

pp. 63-73

Author(s):

Serah F. Ige ◽

Waliyat O. Aremu ◽

Bolade S. Olateju ◽

Victor A. Oladipupo ◽

Adedayo T. Adekola

Keyword(s):

Ulcerative Colitis ◽

Superoxide Dismutase ◽

Acetic Acid ◽

Adult Female ◽

Adult Male ◽

Wistar Rats ◽

Female Rats ◽

Male Rats ◽

Cell Numbers ◽

Age And Sex

Aims: Ulcerative colitis is a disease of the bowel that occurs in all ages and affects both males and females. This research study was designed to investigate the effect of age and sex on the healing of colitis in rats. Methodology: Twenty - eight rats were randomly distributed into four groups of seven animals per group; adult male rats, mid age male rats, adult female rats and mid age female rats. Mid age and adult Wistar rats were 7- 8weeks and 14 weeks old respectively. Colitis was induced through a single intra-colonic instillation of 7% acetic acid (1mL/100g body weight) and allowed to heal for 14 days. Blood samples were obtained for analysis. Colon samples were also obtained for histomorphological study and biochemical assays (Myeloperoxidase activities, Superoxide dismutase, Glutathione, Catalase and Malondialdehyde) levels. Results: There was no significant difference in Malondialdehyde concentration, catalase, Superoxide dismutase, Myeloperoxidase, Platelet Distribution Width, Platelet Count, Basophil cell numbers, Eosinophil cell numbers, platelet cells, Mean Platelet Volume , Mean Cell Volume and white blood cells across the groups. The Glutathione concentration in mid age male rats was significantly increased when compared with adult male rats. The haemoglobin , Lymphocytes and Mean Cell Haemoglobin levels were increased while neutrophils and monocyte levels were decreased in the younger female rats. The histomorphological study revealed poorly preserved surface epithelia layer of the colon in adult male rats while mid age male and female rats showed moderately preserved surface epithelia layer, adult female rats showed normal surface epithelia layer. Conclusion: Mid age rats heal faster than adult rats while in terms of sex, female rats tends to heal faster than male rats.

Download Full-text

Insulin sensitivity, leptin, adiponectin, resistin, and testosterone in adult male and female rats after maternal-neonatal separation and environmental stress

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00271.2017 ◽

2018 ◽

Vol 314 (1) ◽

pp. R12-R21 ◽

Cited By ~ 14

Author(s):

Hershel Raff ◽

Brian Hoeynck ◽

Mack Jablonski ◽

Cole Leonovicz ◽

Jonathan M. Phillips ◽

...

Keyword(s):

Insulin Resistance ◽

Adult Male ◽

Rat Model ◽

Female Rats ◽

Male Rats ◽

Male And Female ◽

Neonatal Hypoxia ◽

Male And Female Rats ◽

Plasma Leptin ◽

Neonatal Separation

Care of premature infants often requires parental and caregiver separation, particularly during hypoxic and hypothermic episodes. We have established a neonatal rat model of human prematurity involving maternal-neonatal separation and hypoxia with spontaneous hypothermia prevented by external heat. Adults previously exposed to these neonatal stressors show a sex difference in the insulin and glucose response to arginine stimulation suggesting a state of insulin resistance. The current study used this cohort of adult rats to evaluate insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR)], plasma adipokines (reflecting insulin resistance states), and testosterone. The major findings were that daily maternal-neonatal separation led to an increase in body weight and HOMA-IR in adult male and female rats and increased plasma leptin in adult male rats only; neither prior neonatal hypoxia (without or with body temperature control) nor neonatal hypothermia altered subsequent adult HOMA-IR or plasma adiponectin. Adult male-female differences in plasma leptin were lost with prior exposure to neonatal hypoxia or hypothermia; male-female differences in resistin were lost in the adults that were exposed to hypoxia and spontaneous hypothermia as neonates. Exposure of neonates to daily hypoxia without spontaneous hypothermia led to a decrease in plasma testosterone in adult male rats. We conclude that neonatal stressors result in subsequent adult sex-dependent increases in insulin resistance and adipokines and that our rat model of prematurity with hypoxia without hypothermia alters adult testosterone dynamics.

Download Full-text

PROLACTIN STIMULATION TEST WITH PERPHENAZINE: AN EVALUATION OF PLASMA PROLACTIN LEVELS AND PITUITARY SECRETORY ACTIVITY IN THE RAT

Journal of Endocrinology ◽

10.1677/joe.0.0680355 ◽

1976 ◽

Vol 68 (3) ◽

pp. 355-368 ◽

Cited By ~ 12

Author(s):

A. A. VAN DER GUGTEN ◽

P. C. SAHULEKA ◽

G. H. VAN GALEN ◽

H. G. KWA

Keyword(s):

Adult Male ◽

Secretory Activity ◽

Female Rats ◽

Male Rats ◽

Plasma Prolactin ◽

Prolactin Release ◽

Oestrogen Treatment ◽

Endocrine Status ◽

Pituitary Prolactin ◽

Single Plasma

SUMMARY Many investigations of the regulation of prolactin synthesis and release are based on single plasma prolactin determinations. The purpose of the present experiment was to ascertain whether groups of rats (i.e. young or adult, male or female animals, being either intact, gonadectomized or gonadectomized and treated with oestrone), differing in age and/or endocrine status, will react to a single dose of perphenazine by an acute release of pituitary prolactin in proportion to their initial plasma prolactin levels. No consistent relation existed between the classification of the twelve groups of rats into three categories of basal plasma prolactin levels (i.e. < 20, 25–50, > 125 ng/ml) and their response to perphenazine. Even though all groups showed a highly significant increase of plasma prolactin levels the magnitude of the maximum prolactin response at 30 min varied greatly within the groups of one category and thus was not related to the initial prolactin levels. The effect of 14 days of oestrone treatment in increasing plasma prolactin levels in gonadectomized animals was greatest in young and adult male rats, less in young females and not significant in adult females. The results obtained after perphenazine treatment in the latter group made it clear that the effect of oestrogen treatment on prolactin release can be completely blocked by increasing synthesis and/or release of the prolactin-release inhibiting factor (PIF). Since perphenazine induces decrease of pituitary prolactin and a concomitant increase of plasma prolactin levels through lowered PIF-action, the positive effect of oestrogens on prolactin release (as observed in gonadectomized male and young female rats) apparently is caused by a different mode of action. The implications of these findings for the regulation of prolactin release, as affected by the endocrine status of the rat, is discussed. Moreover, comparison of prolactin lost from the pituitary and gained in the circulation of the experimental animals, with amounts of prolactin that were observed to disappear from plasma during the experiment, provided suggestive evidence that the capacity to synthesize and/or eliminate prolactin, after a sudden provoked release of the hormone, differed among the groups. The rates of synthesis by the pituitary, of release from the pituitary into the circulation as well as of elimination of the hormone from the circulation (equally involved in determining actual plasma levels) are thought, therefore, to be far more important for the elucidation of prolactin regulation than single plasma prolactin determinations.

Download Full-text

Male-specific suppression of hepatic microsomal UDP-glucuronosyl transferase activities toward sex hormones in the adult male rat administered bisphenol A

Biochemical Journal ◽

10.1042/bj20020804 ◽

2002 ◽

Vol 368 (3) ◽

pp. 783-788 ◽

Cited By ~ 22

Author(s):

Noriaki SHIBATA ◽

Junya MATSUMOTO ◽

Ken NAKADA ◽

Akira YUASA ◽

Hiroshi YOKOTA

Keyword(s):

Bisphenol A ◽

Mrna Expression ◽

Sex Hormones ◽

Adult Male ◽

Endocrine Disruptor ◽

Liver Microsomes ◽

Female Rats ◽

Male Rats ◽

Male Rat ◽

Blotting Analysis

Various adverse effects of endocrine disruptors on the reproductive organs of male animals have been reported. We found that UDP-glucuronosyltransferase (UGT) activities towards bisphenol A, testosterone and oestradiol were significantly decreased in liver microsomes prepared from adult male Wistar rats administered with the endocrine disruptor bisphenol A (1mg/2 days for 2 or 4 weeks). However, suppression of the transferase activities was not observed in female rats, even after bisphenol A treatment for 4 weeks. Diethylstilbestrol, which is well known as an endocrine disruptor, had the same effects, but p-cumylphenol had no effect on UGT activities towards sex hormones. Co-administration of an anti-oestrogen, tamoxifen, inhibited the suppression of the transferase activities by bisphenol A. Western blotting analysis showed that the amount of UGT2B1, an isoform of UGT which glucuronidates bisphenol A, was decreased in the rat liver microsomes by the treatment. Northern blotting analysis also indicated that UGT2B1 mRNA in the liver was decreased by bisphenol A treatment. The suppression of UGT activities, UGT2B1 protein and UGT2B1 mRNA expression did not occur in female rats. The results indicate that bisphenol A treatment reduces the mRNA expression of UGT2B1 and other UGT isoforms that mediate the glucuronidation of sex hormones in adult male rats, and this suggests that the endocrine balance may be disrupted by suppression of glucuronidation.

Download Full-text

N-(3,5-dinitrophenyl)-5-methoxytryptamine, a novel melatonin antagonist: effects on sexual maturation of the male and female rat and on oestrous cycles of the female rat

Journal of Endocrinology ◽

10.1677/joe.0.1160043 ◽

1988 ◽

Vol 116 (1) ◽

pp. 43-53 ◽

Cited By ~ 27

Author(s):

M. Laudon ◽

Z. Yaron ◽

N. Zisapel

Keyword(s):

Drinking Water ◽

Adult Female ◽

Sexual Maturation ◽

Young Male ◽

Female Rats ◽

Male Rats ◽

Female Rat ◽

Simultaneous Administration ◽

Serum Concentrations ◽

The Brain

ABSTRACT N-(3,5-dinitrophenyl)-5-methoxytryptamine (ML-23) has recently been synthesized and shown to antagonize the inhibitory effect of melatonin on the release of dopamine in vitro from the hypothalamus of female rats. In the present study the ability of ML-23 to inhibit in vivo the following melatonin-mediated effects was investigated: (1) delayed sexual maturation of young male rats, (2) delayed sexual maturation of young female rats, (3) inhibition of ovulation in mature female rats and (4) re-establishment of oestrous cycles in adult female rats maintained in continuous light. The inhibitory effect of daily melatonin injections, given in the afternoon, on the growth of the prostate gland and seminal vesicles and on serum testosterone concentrations in young male rats was prevented by daily injections of ML-23. Daily injections of ML-23 alone did not affect sexual maturation of young rats. In young male rats treated through the drinking water with melatonin, the growth of the accessory sex organs, but not that of the testes, was delayed and serum concentrations of testosterone were lower than in untreated rats. Administration of ML-23 through the drinking water increased serum concentrations of testosterone but did not significantly affect the weights of the accessory sex organs. Simultaneous administration of ML-23 and melatonin through the drinking water prevented completely, in a dose-dependent manner, the melatonin-mediated decrease in epididymal weights and in serum concentrations of testosterone and partially inhibited the delayed growth of the prostate glands and seminal vesicles. In young female rats treated with melatonin through the drinking water for 30 days, the growth of the ovaries was inhibited and serum concentrations of oestradiol were lower than in untreated rats. The growth of the uterus was not significantly affected. Administration of ML-23 through the drinking water did not significantly affect uterine and ovarian weights or oestradiol concentrations. Simultaneous administration of melatonin and ML-23 through the drinking water prevented completely the melatonin-mediated decrease in ovarian weights and in serum oestradiol concentrations. Ovulation during presumptive oestrus was prevented in adult female rats treated through the drinking water for 7 days with melatonin. Administration of ML-23 alone did not significantly affect the average numbers of ova shed and corpora lutea present. Simultaneous administration of ML-23 and melatonin prevented completely the melatonin-mediated inhibition of ovulation; the average number of ova shed was the same as in controls. Suppression of reproductive cycles occurred in adult female rats after long-term exposure to continuous light. This suppression was prevented by daily injections of melatonin in the afternoon; the incidence of constant oestrus decreased by 80%. Simultaneous injection of ML-23 and melatonin into rats maintained under continuous illumination prevented the effect of melatonin, and all the animals remained in constant oestrus. Administration of ML-23 alone did not alter the incidence of constant oestrus. A tritium-labelled derivative of ML-23 was prepared and administered orally to male rats. Peak concentrations of ML-23 occurred in the blood within 30 min after feeding and disappeared subsequently with a half-life of about 42 min. Intraperitoneal injection of [3H]ML-23 resulted in the appearance of peak concentrations of the drug in the brain within 20 min. The effects of ML-23 on serotonin S1 and S2 receptors, dopamine D2 receptors and melatonin receptors in the brain of the male rat were investigated using [3H]serotonin, [3H]spiperone and 2-[125I]iodomelatonin respectively. The binding of [3H]serotonin to brain synaptosomes and of [3H]spiperone to synaptosomes prepared from the cortical and caudate regions of the cerebrum was unaffected by ML-23 (10 μmol/l), whereas the binding of 2-[125I]iodomelatonin to brain synaptosomes was entirely inhibited. The results demonstrate the potency of ML-23 in antagonizing melatonin-mediated effects in the male and female rat in vivo. The drug may be administered to the animals simply through the drinking water, for relatively long periods without apparent deleterious effects on survival and welfare. ML-23 is accessible to both central and peripheral sites and acts specifically on melatonin but not on serotonin or dopamine receptors in the brain. The availability of a melatonin antagonist offers new opportunities for exploring the physiological role of melatonin in the neuroendocrine system. J. Endocr. (1988) 116, 43–53

Download Full-text

Variation in tissue carnitine concentrations with age and sex in the rat

Biochemical Journal ◽

10.1042/bj1760677 ◽

1978 ◽

Vol 176 (3) ◽

pp. 677-681 ◽

Cited By ~ 47

Author(s):

Peggy R. Borum

Keyword(s):

Skeletal Muscle ◽

Adult Male ◽

Human Subject ◽

The Body ◽

Female Rats ◽

Male Rats ◽

Adult Females ◽

Weanling Rats ◽

Carnitine Metabolism ◽

Carnitine Concentration

Diabetes, starvation and various hormonal treatments are known to alter drastically carnitine concentrations in the body. Before the mechanisms controlling carnitine metabolism could be determined, it was necessary to establish normal carnitine concentrations in both sexes at different ages. Carnitine was assayed in plasma, liver, heart and skeletal muscle of rats from birth to weaning. The plasma carnitine increased rapidly during the first 2 days after birth. Carnitine in both heart and skeletal muscle increased, whereas liver concentrations declined during the first week of life. A carnitine-free diet containing sufficient precursors for carnitine biosynthesis was fed to weanling rats. Groups of ten male and ten female rats were killed each week for 10 consecutive weeks. Carnitine was determined in plasma, liver, heart, skeletal muscle, urine and epididymis in the male. There was no difference in carnitine concentrations between the sexes at weaning. Plasma, heart and muscle concentrations were higher in adult male rats than in adult females. However, liver carnitine and urinary carnitine concentrations were higher in adult female than in adult male rats. The epididymal carnitine concentration increased very rapidly during 50 to 70 days of age and the differences in carnitine concentrations between the sexes also became apparent during this time. Thus both the age and the sex of the human subject or experimental animal must be considered when investigating carnitine metabolism.

Download Full-text