Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to survival until well-balanced amino acid sources are found

Contraception in older woman.

Oral contraception (OC) in the premenopause has been recently proposed as treatment for control and prevention of the putative symptoms typical of this period of life. Indeed, menstrual cycle disturbances and climacteric symptoms frequently occur at this age. The major aim of normal contraception is resultant maintenance of normal sexual activity. The effects of one OC containing 20 mcg ethinylestradiol and 150 mcg desogestrel (EE/DOG) were studied. Treatment did not significantly modify both lipid metabolism (triglycerides, total cholesterol, HDL, LDL, Apo A, Apo B) and clotting system (fibrinogen, PT, PTT, antithrombin III, fibrinopeptide A). No significant modifications of oral glucose tolerance test (OGGT) occurred after EE/DOG treatment. Also, bone density was not modified during estro-progestinic administration. From our experience, if there are no risk factors such as smoking, obesity or hypertension, the OCs could be used until menopause for absolute contraceptive efficacy, good tolerance and lack of side effects. PIP: At Cagliari Hospital in Italy, the department of obstetrics and gynecology studied the efficacy and safety of a combined oral contraceptive (OC) containing 20 mcg of ethinyl estradiol and 150 mcg of desogestrel in 61 nonsmoking women aged 41-48. The women were followed for up to five years. After the second cycle of treatment, the mean length of the menstrual cycle and menses standardized at 26 and 4 days, respectively. By 12 months of OC treatment, the slight side effects either had disappeared or had significantly declined. No woman gained weight. Blood pressure did not change significantly. Lipid metabolism did not change significantly. There were only small insignificant increases in high and low density lipoprotein cholesterol, triglycerides, and apolipoproteins A. After 6, 12, and 24 months of OC treatment, sex hormone binding globulin levels increased significantly (1.83 vs. 3.6 mcg/dl; p 0.05). The OC did not significantly affect blood coagulation markers (fibrinogen, prothrombin time, partial thromboplastin time, antithrombin III, and fibrinopeptide A). It had no effect on fasting blood glucose and insulin levels and their response to the oral glucose tolerance test. The researchers conducted bone density measurements in the lumbar spine (L2-L4) of 37 women aged 45-48. The OC did not alter bone density. These results suggest that this low-estrogen-dose combined OC is a safe and effective contraceptive in perimenopausal women and has good acceptability and good cycle control without considerable side effects. The OC also exhibited the capability of further minimizing the thrombogenic effects of low-dose OCs

Specific concordance index defines the physiological lag between LH and progesterone in women during the midluteal phase of the menstrual cycle.

Using a recently developed statistically based method for assessment of the degree of concordance, we evaluated the degree of specific concordance (SC) between luteinizing hormone (LH) and progesterone secretory patterns. Eight healthy women volunteered for this study, undergoing a 12-h pulsatility study, sampling every 10 min. LH and progesterone pulse frequencies were estimated with the program DETECT (9.75 +/- 1 and 11.5 +/- 0.9 pulses/12 h, respectively; mean +/- SEM). The temporal relationship between LH and progesterone secretions was evaluated with cross-correlation analysis and with the computation of the SC index. Cross-correlation showed concordance between LH and progesterone (p less than 0.05) at a range of lag between 0 and 40 min, while the SC index indicated that LH and progesterone pulses were significantly (p less than 0.05) and maximally correlated at 10-min lag. In conclusion, our data demonstrated that the specific concordance confirms the statistically significant concordance of LH and progesterone secretory events in women during the midluteal phase. In addition, the use of this new, objective, statistically based approach permits, compared to traditional cross-correlation analysis, a more precise definition of the physiological time lag for temporal coupling of secretory events between the two hormones

Specific concordance index defines the physiological lag between LH and progesterone in women during the midluteal phase of the menstrual cycle.

Using a recently developed statistically based method for assessment of the degree of concordance, we evaluated the degree of specific concordance (SC) between luteinizing hormone (LH) and progesterone secretory patterns. Eight healthy women volunteered for this study, undergoing a 12-h pulsatility study, sampling every 10 min. LH and progesterone pulse frequencies were estimated with the program DETECT (9.75 +/- 1 and 11.5 +/- 0.9 pulses/12 h, respectively; mean +/- SEM). The temporal relationship between LH and progesterone secretions was evaluated with cross-correlation analysis and with the computation of the SC index. Cross-correlation showed concordance between LH and progesterone (p less than 0.05) at a range of lag between 0 and 40 min, while the SC index indicated that LH and progesterone pulses were significantly (p less than 0.05) and maximally correlated at 10-min lag. In conclusion, our data demonstrated that the specific concordance confirms the statistically significant concordance of LH and progesterone secretory events in women during the midluteal phase. In addition, the use of this new, objective, statistically based approach permits, compared to traditional cross-correlation analysis, a more precise definition of the physiological time lag for temporal coupling of secretory events between the two hormones