THE DURATION OF THE EFFECT OF ISOLOGOUS PITUITARY IMPLANTS ON THE ESTROUS CYCLES IN THE INTACT MOUSE

1963 ◽  
Vol 41 (1) ◽  
pp. 101-106
Author(s):  
E. Odette Hagen ◽  
H. E. Rawlinson

Implantations of pituitary isografts into intact female mice cause marked irregularity and lengthening in estrous cycles. This phenomenon can be produced by a single implantation of two pituitaries. The effect is still apparent 10 to 12 months later. It can be produced although in reduced degree by implantations into animals a year old. The basic mechanism is considered to be a more sustained production of prolactin by the graft. The effects of such transplants are maintained for several months.

1963 ◽  
Vol 41 (1) ◽  
pp. 101-106 ◽  
Author(s):  
E. Odette Hagen ◽  
H. E. Rawlinson

Implantations of pituitary isografts into intact female mice cause marked irregularity and lengthening in estrous cycles. This phenomenon can be produced by a single implantation of two pituitaries. The effect is still apparent 10 to 12 months later. It can be produced although in reduced degree by implantations into animals a year old. The basic mechanism is considered to be a more sustained production of prolactin by the graft. The effects of such transplants are maintained for several months.


2012 ◽  
Vol 53 (4) ◽  
pp. 374-384 ◽  
Author(s):  
Paula A. Witt-Enderby ◽  
John P. Slater ◽  
Nakpangi A. Johnson ◽  
Corry D. Bondi ◽  
Balasunder R. Dodda ◽  
...  

Author(s):  
C.D. Bondi ◽  
C. Alonso-Gonzalez ◽  
W.P. Clafshenkel ◽  
M.P. Kotlarczyk ◽  
B.R. Dodda ◽  
...  

2014 ◽  
Vol 306 (7) ◽  
pp. H938-H953 ◽  
Author(s):  
Jennifer K. MacDonald ◽  
W. Glen Pyle ◽  
Cristine J. Reitz ◽  
Susan E. Howlett

This study established conditions to induce regular estrous cycles in female C57BL/6J mice and investigated the impact of the estrous cycle on contractions, Ca2+ transients, and underlying cardiac excitation-contraction (EC)-coupling mechanisms. Daily vaginal smears from group-housed virgin female mice were stained to distinguish estrous stage (proestrus, estrus, metestrus, diestrus). Ventricular myocytes were isolated from anesthetized mice. Contractions and Ca2+ transients were measured simultaneously (4 Hz, 37°C). Interestingly, mice did not exhibit regular cycles unless they were exposed to male pheromones in bedding added to their cages. Field-stimulated myocytes from mice in estrus had larger contractions (∼2-fold increase), larger Ca2+ transients (∼1.11-fold increase), and longer action potentials (>2-fold increase) compared with other stages. Larger contractions and Ca2+ transients were not observed in estrus myocytes voltage-clamped with shorter action potentials. Voltage-clamp experiments also demonstrated that estrous stage had no effect on Ca2+ current, EC-coupling gain, diastolic Ca2+, sarcoplasmic reticulum (SR) Ca2+ content, or fractional release. Although contractions were largest in estrus, myofilament Ca2+ sensitivity was lowest (EC50 values ∼1.15-fold higher) in conjunction with increased phosphorylation of myosin binding protein C in estrus. Contractions were enhanced in ventricular myocytes from mice in estrus because action potential prolongation increased SR Ca2+ release. These findings demonstrate that cyclical changes in reproductive hormones associated with the estrous cycle can influence myocardial electrical and contractile function and modify Ca2+ homeostasis. However, such changes are unlikely to occur in female mice housed in groups under conventional conditions, since these mice do not exhibit regular estrous cycles.


2018 ◽  
Vol 314 (2) ◽  
pp. H330-H342 ◽  
Author(s):  
Seong Chul Kim ◽  
Austin C. Boese ◽  
Matthew H. Moore ◽  
Rea M. Cleland ◽  
Lin Chang ◽  
...  

Estrogen has been shown to affect vascular reactivity. Here, we assessed the estrogen receptor-α (ERα) dependency of estrogenic effects on vasorelaxation via a rapid nongenomic pathway in both male and ovary-intact female mice. We compared the effect of a primary estrogen, 17β-estradiol (E2) or 4,4′,4″-(4-propyl-[1H]pyrazole-1,3,5-triyl)tris-phenol (PPT; selective ERα agonist). We found that E2 and PPT induced greater aortic relaxation in female mice than in male mice, indicating ERα mediation, which was further validated by using ERα antagonism. Treatment with 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP dihydrochloride; ERα antagonist) attenuated PPT-mediated vessel relaxation in both sexes. ERα-mediated vessel relaxation was further validated by the absence of significant PPT-mediated relaxation in aortas isolated from ERα knockout mice. Treatment with a specific ERK inhibitor, PD-98059, reduced E2-induced vessel relaxation in both sexes but to a lesser extent in female mice. Furthermore, PD-98059 prevented PPT-induced vessel relaxation in both sexes. Both E2 and PPT treatment activated ERK as early as 5–10 min, which was attenuated by PD-98059 in aortic tissue, cultured primary vascular smooth muscle cells (VSMCs), and endothelial cells (ECs). Aortic rings denuded of endothelium showed no differences in vessel relaxation after E2 or PPT treatment, implicating a role of ECs in the observed sex differences. Here, our results are unique to show estrogen-stimulated rapid ERα signaling mediated by ERK activation in aortic tissue, as well as VSMCs and ECs in vitro, in regulating vascular function by using side-by-side comparisons in male and ovary-intact female mice in response to E2 or PPT. NEW & NOTEWORTHY Here, we assessed the estrogen receptor-α dependency of estrogenic effects in vasorelaxation of both male and ovary-intact female mice by performing side-by-side comparisons. Also, we describe the connection between estrogen-stimulated rapid estrogen receptor-α signaling and downstream ERK activation in regulating vascular function in male and ovary-intact female mice.


Endocrinology ◽  
2020 ◽  
Vol 161 (8) ◽  
Author(s):  
Alexandra L Cara ◽  
Martin G Myers ◽  
Carol F Elias

Abstract Disorders of androgen imbalance, such as hyperandrogenism in females or hypoandrogenism in males, increase risk of visceral adiposity, type 2 diabetes, and infertility. Androgens act upon androgen receptors (AR) which are expressed in many tissues. In the brain, AR are abundant in hypothalamic nuclei involved in regulation of reproduction and energy homeostasis, yet the role of androgens acting via AR in specific neuronal populations has not been fully elucidated. Leptin receptor (LepRb)–expressing neurons coexpress AR predominantly in hypothalamic arcuate and ventral premammillary nuclei (ARH and PMv, respectively), with low colocalization in other LepRb neuronal populations, and very low colocalization in the pituitary gland and gonads. Deletion of AR from LepRb-expressing cells (LepRbΔAR) has no effect on body weight, energy expenditure, and glucose homeostasis in male and female mice. However, LepRbΔAR female mice show increased body length later in life, whereas male LepRbΔAR mice show an increase in spontaneous ambulatory activity. LepRbΔAR mice display typical pubertal timing, estrous cycles, and fertility, but increased testosterone levels in males. Removal of sex steroid negative feedback action induced an exaggerated rise in luteinizing hormone in LepRbΔAR males and follicle-stimulating hormone in LepRbΔAR females. Our findings show that AR can directly affect a subset of ARH and PMv neurons in a sex-specific manner and demonstrate specific androgenic actions in the neuroendocrine hypothalamus.


1955 ◽  
Vol 13 (1) ◽  
pp. 94-100 ◽  
Author(s):  
JUNE EAST

SUMMARY Synthetic genistein, 5:7:4′-trihydroxy-isoflavone, proved to be oestrogenic (that is to say produced vaginal cornification) when included in the normal diet of immature, spayed and intact female mice in amounts calculated to give daily intakes of 2, 10 and 15 mg respectively. Consumption of genistein also precipitated vaginal opening in immature mice. The fertility of adult male mice fed 15 mg genistein daily for 22–25 days was more severely affected than that of adult females similarly treated for 31–55 days. Of ten males, five were rendered sterile and the fertility of three others was impaired. Two of ten females did not mate and abnormal numbers of still-born young were produced by the remaining animals. Four males and one female did not recover fertility when transferred to normal rations.


1989 ◽  
Vol 121 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Kaoru Nomura ◽  
David W. Puett ◽  
David Puett ◽  
Kazuo Shizume ◽  
Grant W. Liddle

Abstract. LH is composed of isoforms which exhibit microheterogeneity. We recently demonstrated that a particular ovine or porcine LH preparation (G100-fr.3) stimulates kidney growth. This study was conducted to clarify the physiological role of this renotropic activity and other extragonadal effects of the ovine LH preparation in CD-1 mice. Hypophysectomy caused a significantly greater reduction in relative dry kidney weight (i.e. g/100 g body weight) when compared to adrenalectomy, castration, thyroidectomy, and castration plus thyroidectomy. Supplementation with G100-fr.3 in these animals partially restored not only kidney size but also DNA, RNA and protein content. Treatment with standard LH preparations (NIDDKoLH24 and G3-268DA), as well as PRL, GH, FSH and TSH, failed to reverse the renal atrophy induced by hypophysectomy and castration. Administration of testosterone to castrated hypophysectomized mice increased kidney weight and RNA content, but not renal DNA. The relative dry kidney weight increased significantly at the onset of puberty in intact male mice, but not in castrated males or intact female mice. In addition, human CG increased kidney size in hypophysectomized male mice, but not in castrated hypophysectomized animals. These findings indicate that LH isoforms may regulate kidney growth in the male mouse both directly as a renotropin stimulating hyperplasia and indirectly as a gonadotropin via testicular androgen, producing cellular hypertrophy. It was also noted that G100-fr.3 decreased hepatic weight, DNA, RNA and protein, but produced no significant change in the spleen, heart or adrenal glands in castrated-hypophysectomized mice. Such extragonadal effects of G100-fr.3 were also observed in intact female mice. These results suggest that certain LH isoforms may have extragonadal actions involving the kidney and liver.


2017 ◽  
Vol 35 (1) ◽  
pp. 71
Author(s):  
Siska Adelya Ramadhani ◽  
Iman Supriatna ◽  
Ni Wayan Kurniani Karja ◽  
Adi Winarto

Gosipol is a substances contained in extracted cotton seed which is thought to have the antifertility ability therefore it is often used as a herbal contraceptive. The aim of this study were to assess the folliculogenesis in mice after administrated with cottonseed extract. 60 female mice strain DDY which was 14-15 weeks old and 30-35 g body weight were divided into five groups and given cottonseed extract each 0; 1,5; 2,1 and 2,7 g/kg BW for 5, 10, 15, 24, and 24 + 10 days (without cottonseed treatment). At the end of the treatment period, mice was euthanasia to observe follicular development histomorphology (each three mice of each treatment). Mice estrous status were evaluated based on the description of the vaginal smear cells with Giemsa staining. The results showedthat the number of developing follicles was low (P < 0.05) compared with control after 5 days cottonseed extract administration at dose 2,7 g/kg BW that were 23 ± 3,6. At dose 1,5 and 2,1 g/kg BW the number of follicles was low after 24 days that were 25 ± 10,4 and 27 ± 3,5. Recovery effects of follicle number after cottonseed extract administration for 24 days was the best at a dose of 1,5 g/kg BW. Prolonge of estrous cycle occured in mice which were administrated the cottonseed extract of at all dose treatment. In conclusion, although the decrease in the number of developing follicles and prolonge of estrous cycles occurred after cottonseed extract administration, but these effects are reversible after the administration ended.


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