Gender Differences of Preptin Levels in Rat Models of Hypogonadism

Abstract

Background: Preptin is a peptide hormone co-secreted with insulin and amylin from pancreatic β cells. Preptin has an in vitro and in vivo osteogenic effect.

Aim: we hypothesized that preptin levels will be different in both sexes and these sexual differences might play a potential role in bone thickness differences.

Material and methods: 80 albino rats were divided into 8 groups, Male Control (MC), Male Hypogonadised (MH), Male Hypogonadised with testosterone replacement (MHT), Female Control (FC), Female Hypogonadised (FH) and Female Hypogonadised with estradiol replacement (FHE), Female Hypogonadised with progesterone replacement (FHP) and Female Hypogonadised with estradiol and progesterone replacement (FHEP) groups.

Results: preptin levels were decreased significantly (p≤0.001) from 41.58±10.5 in MC group to 21.58±9.6 in MH group. Preptin level was increased significantly (p≤0.001) with testosterone replacement from 21.58±9.6 to 40.53±10.4. No significant differences (p=0.8) between MC group and MHT group. Preptin level was also decreased significantly (p≤0.001) from 31.21±8.3 in FC group to 13.30±7.6 in FH group and 17.18±7.5 in FHP group.  Insignificant differences (p=0.2) were found in preptin level in FHE and FHEP group compared with FC group. Preptin levels in males were found to be significantly (p=0.02) higher in MC group (41.58±10.5) than FC (31.21±8.3). Also, there are significant differences (p=0.04) between preptin levels in MH group (21.58±9.6) and FH group (13.30±7.6) although both of them are reduced significantly in comparison with the control groups. In addition, preptin levels are significantly (p=0.02) lower in FHEP (30.21±8.1) compared with male hypogonadised with testosterone (40.53±10.4).

Conclusion: preptin levels are different in both sexes and these sexual differences might play a potential role in bone thickness differences and these levels are also different within the same sex according to presence or absence of sex hormones.