Serum specific vasopressin-degrading activity is related to blood total cholesterol levels in men but not in women.

The role of vasopressin (AVP) in the pathophysiology of cardiovascular disease is controversial, but this peptide hormone is elevated in heart failure and some forms of hypertension. Also, AVP has vasoconstrictor, mitogenic, hyperplasic and renal fluid retaining properties which, by analogy with angiotensin II, may have deleterious effects when present in chronic excess. Furthermore, cholesterol blood levels are also associated with hypertension, although the underlying mechanism is not known.

Hypothalamus-pituitary-thyroid axis disruption in rats with breast cancer is related to an altered endogenous oxytocin/insulin-regulated aminopeptidase (IRAP) system.

Associations of breast cancer with diseases of the thyroid have been repeatedly reported, but the mechanism underlying this association remains to be elucidated. It has been reported that oxytocin (OXT) attenuates the thyroid-stimulating hormone (TSH) release in response to thyrotrophin-releasing hormone (TRH) and decreased plasma levels of TSH as well as the thyroid hormones by an effect mediated by the central nervous system. Oxytocinase (IRAP) is the regulatory proteolytic enzyme reported to hydrolyze OXT.

Doxazosin blockade of alpha 1-adrenergic receptors increases rat serum progesterone levels: a putative role of ovarian angiotensin III in steroidogenesis.

Objective: To analyze the role of the local renin-angiotensin system (RAS) in the female reproductive system to modulate ovarian steroidogenesis and its relationship with alpha(1)adrenergic receptors.

Design: Observational study.

Setting: University laboratory.

Specific enkephalin-degrading aminopeptidase activity in the HPT and HPO axes of rats with breast cancer induced by N-methyl nitrosourea.

State and function of breast depend on an endocrinological balance, the upsetting of which can be a factor favorable to the development of cancer. Enkephalins (ENK) have been considered as a particular form of adaptation to defense to the organism against neoplastic processes. However, ENK may modify the endocrine functions of glands such as the ovary or the thyroid through the hypothalamus-pituitary axis, acting direct or indirectly as endocrine, paracrine or autocrine stimulatory growth factors.