Dear Rola Hammoud,

Hope these papers below help you:

https://www.ncbi.nlm.nih.gov/pubmed/11355748

https://www.ncbi.nlm.nih.gov/pubmed/10668639

Regards

for Leptin: Rat Leptin Enzyme Immunoassay Kit, SPI-BIO/Bertin Pharma Biotech Division --> sensitivity of 50 pg/mL

for Insulin: Elisa from DRG international --> sensitivity of 40 pg/mL

both work fine with rats from early postnatal stages, check out this paper

Best,

https://www.ncbi.nlm.nih.gov/pubmed/24847697

Thank you!

Dear Rola, These references may be of assistance to you????? 1. Raff H1, Bruder ED, Jankowski BM. The effect of hypoxia on plasma leptin and insulin in newborn and juvenile rats. Endocrine. 1999 Aug;11(1):37-9. Hypoxia leads to a decrease in food intake and attenuated weight gain in rats. The purpose of this study was to measure plasma leptin and insulin in young rats exposed to hypoxia for 7 d as compared to a normoxic control group of the same age. One group was exposed from birth to 7 d of age; the other was exposed from 28 to 35 d of age (weaned at 21 d of age). As expected, body weight was significantly lower in rats of either age exposed to hypoxia for 7 d. Plasma leptin was significantly lower in hypoxic (2.0+/-0.2 ng/mL; n = 41) compared with normoxic (2.6+/-0.3 ng/mL; n = 30) 7-d-old rats. Plasma leptin was also significantly lower in hypoxic (1.1+/-0.1 ng/mL; n = 20) as compared to normoxic (1.5+/-0.1 ng/mL; n = 20) 35-d-old rats. Seven-day-old rats exposed to hypoxia demonstrated significant increases in plasma glucose and insulin whereas 35-d-old rats exhibited a decrease in both variables. We conclude that exposure to hypoxia for 7 d leads to a decrease in body weight and plasma leptin in infant and juvenile rats. The decrease in leptin may be an attempt to reverse hypoxia-induced anorexia. 2. Abdel-Azeem M. El-Mazary, et al. Adiponectin, leptin and insulin levels at birth and in early postnatal life in neonates with hypoxic ischemic encephalopathy. J Diabetes Metab Disord. 2015; 14: 87. 3. Bruder ED1, Jacobson L, Raff H. Plasma leptin and ghrelin in the neonatal rat: interaction of dexamethasone and hypoxia. J Endocrinol. 2005 Jun;185(3):477-84. Ghrelin, leptin, and endogenous glucocorticoids play a role in appetite regulation, energy balance, and growth. The present study assessed the effects of dexamethasone (DEX) on these hormones, and on ACTH and pituitary proopiomelanocortin (POMC) and corticotropin-releasing hormone receptor-1 (CRHR1) mRNA expression, during a common metabolic stress - neonatal hypoxia. Newborn rats were raised in room air (21% O2) or under normobaric hypoxia (12% O2) from birth to postnatal day (PD) 7. DEX was administered on PD3 (0.5 mg/kg), PD4 (0.25 mg/kg), PD5 (0.125 mg/kg), and PD6 (0.05 mg/kg). Pups were studied on PD7 (24 h after the last dose of DEX). DEX significantly increased plasma leptin and ghrelin in normoxic pups, but only increased ghrelin in hypoxic pups. Hypoxia alone resulted in a small increase in plasma leptin. Plasma corticosterone and pituitary POMC mRNA expression were decreased 24 h following the last dose of DEX, whereas plasma ACTH and pituitary CRHR1 mRNA expression had already increased (normoxia and hypoxia). Hypoxia alone increased corticosterone, but had no effect on ACTH or pituitary POMC and CRHR1 mRNA expression. Neonatal DEX treatment, hypoxia, and the combination of both affect hormones involved in energy homeostasis. Pituitary function in the neonate was quickly restored following DEX-induced suppression of the hypothalamic-pituitary-adrenal axis. The changes in ghrelin, leptin, and corticosterone may be beneficial to the hypoxic neonate through the maintenance of appetite and shifts in intermediary metabolism.

Follow this link

https://academic.oup.com/endo/article/149/2/733/2454843

kind regards