In rats, angiotensin II appears to be synthesized in the anterior pituitary gland and stored in gonadotropes in the same granules as the beta-subunit of luteinizing hormone (LH). The gonadotropes also contain renin-like and angiotensin-converting enzyme-like immunoreactivity, but angiotensinogen-like immunoreactivity is found in a separate population of cells and does not colocalize with any of the known anterior pituitary hormones. This suggests that angiotensinogen shuttles to the gonadotropes in a paracrine fashion. There are angiotensin II receptors on lactotropes and corticotropes, but no definite function has been established for pituitary angiotensin II in the regulation of prolactin and adrenocorticotropic hormone.

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Among neurodegenerative diseases, Alzheimer’s disease (AD) is a leading cause of death in elderly individuals. AD is characterized, among other clinical findings, by unexplained weight loss, cachexia and altered immune function. To explore whether any relationship between gender and circulating levels of several eating-controlling metabolites exist, we evaluated leptin, tumor necrosis factor (TNF)-α, triiodothyronine (T₃), free (F) thyroxine (T₄), TSH, PRL, insulin (INS), and cortisol in 15 AD-treated patients (age range 55–82 years): 9 postmenopausal females (without hormone replacement therapy) and 6 males. The results (mean ± SEM) indicated that circulating leptin levels were significantly (p < 0.05) higher in female AD (40.34 ± 11.1 ng/ml) than in male AD (6.07 ± 1.39 ng/ml) patients. The difference found in circulating leptin levels was noticed regardless of BMI (26.75 ± 1.77 and 24.55 ± 1.93 kg/m², in females and males, respectively) and waist:hip ratios (0.91 ± 0.03 and 0.94 ± 0.02, in females and males, respectively). Moreover, serum TNF-α concentrations were also significantly (p < 0.02) higher in AD females (12.24 ± 1.47 pg/ml) than in AD males (6.62 ± 1.44 pg/ml), regardless of TNF-α:BMI ratios (0.50 ± 0.09 and 0.28 ± 0.08, in females and males, respectively; p > 0.05). Finally, no differences were observed between gender (in female and male AD patients, respectively) in circulating levels of T₃ (151.33 ± 9.91 vs. 116 ± 17.04 ng/dl), FT₄ (1.26 ± 0.08 vs. 1.24 ± 0.06 ng/dl), TSH (1.28 ± 0.16 vs. 2.46 ± 0.67 µIU/ml), PRL (10.53 ± 2.47 vs. 12.61 ± 2.37 ng/ml), INS (11.76 ± 1.95 vs. 8.59 ± 1.34 µIU/ml) and cortisol (15.71 ± 1.23 vs. 12.63 ± 1.47 µg/dl). These results indicate that our AD group of patients, with normal corticoadrenal and thyroid functions and normoprolactinemia, displayed a gender-related characteristic in the circulating levels of two very important anorectic signals, leptin and TNF-α, being both higher in female than in male AD patients, regardless of BMI. Our study suggests that increased circulating levels of both anorexigenic adipokines may contribute to the metabolic changes observed in AD females.

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