Journal of Jilin University(Medicine Edition) ›› 2022, Vol. 48 ›› Issue (3): 553-560.doi: 10.13481/j.1671-587X.20220301

• Research in basic medicine •    

Effect of pregnancy on cold defense-induced interscapular brown adipose tissue thermogenesis in famale rats and its mechanism

Xiaoyu HOU1,Ya LI1,Jiangyan XIE1,Yian SONG1,Jie ZHANG2,Jianhui XU2()   

  1. 1.Department of Obstetrics,First Affiliated Hospital,Chengdu Medical College,Chengdu 610500,China
    2.Chengdu Medical College,Key Laboratory of Thermoregulation and Inflammation of Sichuan Higher Education Institutes,Chengdu 610500,China
  • Received:2021-09-04 Online:2022-05-28 Published:2022-06-21
  • Contact: Jianhui XU E-mail:helloxjh@126.com

Abstract:

Objective: To study the effect of pregnancy on the cold defense response in the female rats, and to analyze its mechanism.

Methods

A total of 42 adult female SD rats were selected and divided into non-pregnancy group (n=14), second trimester of pregnancy group (n=14) and third trimester of pregnancy group (n=14). The female rats in second trimester of pregnancy and third trimester of pregnancy groups were mated with the adult male rats, whereas the rats in non-pregnancy group were not. The rats in various groups were anesthetized with urethane and α-chloralose. The abdominal skin of the rats was cooled by ice-cold water for making skin cooling state to establish the cold defense response model. The abdominal skin temperature, rectum temperature and temperature of interscapular brown adipose tissue (iBAT) of the rats in various groups before and after skin cooling were recorded through multichannel temperature measuring system,and the abdominal skin temperature, rectum temperature, and the iBAT sympathetic nerve activity (iBAT SNA) of the rats in various groups before and after skin cooling were monitored by multichannel temperature measuring system and biological signal acquisition system.

Results

Compared with before skin cooling, the skin temperature of the rats in various groups after skin cooling was decreased (P<0.05), the rectum temperature of the rats in various groups after skin cooling had no significant differences(P>0.05). In addition, after skin cooling,there was no significant difference in the decreasing of skin temperature of the rats among various groups(P>0.05);there was no significant difference in the decreasing of rectum temperature of the rats among various groups(P>0.05).Compared with before skin cooling, the iBAT temperture of the rats in non-pregnancy and second trimester of pregnancy groups were increased after skin cooling (P<0.05), and there was no significant difference in iBAT temperature of the rats in third trimester of pregnancy group (P>0.05).After skin cooling, compared with non-pregnancy group, the increasing of iBAT temperature of the rats in second trimester of pregnancy group had no significant difference(P>0.05). After skin cooling, compared with non-pregnancy or second trimester of pregnancy groups, the increasing of iBAT temperature of the rats in third trimester of pregnancy group was decreased (P<0.05).Compared with before skin cooling,the iBAT SNA of the rats in non-pregnancy group and second trimester of pregnancy group after skin cooling were increased(P<0.05),and the iBAT SNA of the rats in third trimester of pregnancy group had no significant difference(P>0.05).After skin cooling,compared with non-pregnancy group,the increasing of iBAT SNA of the rats in second trimester of pregnancy group had no significant difference(P>0.05);compared with non-pregnancy group and second trimester of pregnancy group,the increasing of iBAT SNA of the rats in third trimester group was decreased(P<0.05).

Conclusion

The cold defense response in the non-pregnancy and second trimester of pregnancy rats is normal, whereas the cold defence response in the third trimester of pregnancy rats is reduced.This phenomenon is related to the normal cold defensive iBAT SNA in the non-pregnancy and second trimester of pregnancy rats, while the cold defensive iBAT SNA in the third trimester of pregnancy rats is inhibited.

Key words: Pregnancy, Cold defense responses, Brown adipose tissue, Sympathetic nerve activity, Thermoregulation

CLC Number: 

  • R714