Hormonal daily variation co-varies with immunity in captive male bullfrogs (Lithobates catesbeianus).

Abstract:

:Almost all physiological processes within the organism, including immune parameters and hormones, follow a circadian rhythm. These daily fluctuations are often observed in free-living organisms; however, little is known regarding hormonal and immune daily variations in anurans, particularly under laboratory conditions. This study aimed to investigate the hormonal and immune daily variation in captive-bred Bullfrogs (Lithobates catesbeianus) under constant conditions (21 °C and 12:12 LD cycle). Our results showed a daily variation for plasma corticosterone (CORT), testosterone (T), and melatonin (MEL), as well as for blood leukocyte profile, phagocytic activity, and plasma bacterial killing ability (BKA). Hormonal profile and immune activity were higher at the dark when compared with the light phase; however, monocytes and lymphocytes followed the opposite pattern. Moreover, CORT was positively correlated with phagocytosis percentage of blood cells, BKA, and monocytes, while MEL and T showed a positive correlation with PP. Our results demonstrate the daily covariation of different immune variables and immunomodulatory hormones. These 24 h-day variations and covariation certainly have broad implications and need to be considered for better understanding anuran physiology both in the context of laboratory and field studies.

journal_name

Gen Comp Endocrinol

authors

Titon SCM,Titon Junior B,Assis VR,Vasconcelos-Teixeira R,Garcia Neto PG,Lima AS,Ferreira LF,Fernandes PA,Gomes FR,Markus RP

doi

10.1016/j.ygcen.2020.113702

subject

Has Abstract

pub_date

2020-12-20 00:00:00

pages

113702

eissn

0016-6480

issn

1095-6840

pii

S0016-6480(20)30455-X

journal_volume

303

pub_type

杂志文章