Acute phase protein levels in pregnancy and oestrus cycle in bitches Pinar Alkim Ulutas a, * , Bayazit Musal b , Funda Kiral a , Aysegul Bildik a a Department of Biochemistry, Faculty of Veterinary Medicine, University of Adnan Menderes, PK 17, 09016 Aydin, Turkey b Department of of Obstetrics and Reproductive Diseases, Faculty of Veterinary Medicine, University of Adnan Menderes, Aydın, Turkey article info Article history: Accepted 9 September 2008 Keywords: Acute phase proteins Pregnancy Oestrus cycle Canine abstract The purpose of this study was to evaluate the acute phase protein (serum amyloid A, C-reactive protein, haptoglobin, ceruloplasmin and fibrinogen) profiles in pregnant dogs as well as bitches at various stages of the estrus cycle and to verify possible relationship(s) among the APPs profile and hormonal status. A total of 60 bitches of various breeds were enrolled. The animals were divided into six groups. B-mode ultrasonographic scanner (concept M/C) was used for pregnancy diagnosis, involving the first and second halves of pregnancy. Proestrus, estrus, diestrus and anestrus stages of sexual cycles were differentiated by use of vaginal cytology and blood progesterone and estradiol 17-b levels. Serum C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin, ceruloplasmin and fibrinogen levels were determined. No statisti- cally significant differences were observed between the groups with regard to the serum SAA and CRP concentrations. Haptoglobin, ceruloplasmin and fibrinogen concentrations were elevated in pregnant dogs compared to non-pregnant groups’, independently from the pregnancy stage. No statistically signif- icant differences in acute phase protein concentrations in dogs at various stages of estrus could be detected. Results of this study indicated that ceruloplasmin and fibrinogen levels may have potential importance in the diagnosis of pregnancy, and acute phase proteins may be used for monitoring the health status of the pregnant dogs. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction The acute phase response is the part of the innate defence sys- tem of an animal against trauma, inflammation or infection (Gruys et al., 1994; Eckersall, 2000). During this response, there is in- creased production and release of certain plasma proteins known as acute phase proteins (APPs) which include C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin, ceruloplasmin and fibrinogen. Although the biologic functions of APPs remains un- clear, it is apparent that APPs are involved in the regulation of the immune response, inflammation, protection against infection and in the recovery of the damaged tissue (Ceron et al., 2005). Most of the positive acute phase proteins are synthesized by hepatocytes upon stimulation by the pro-inflammatory cytokines, interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF) and re- leased into the blood stream (Gruys et al., 1994; Eckersall, 2000; Ceron et al., 2005). In the dog, levels of acute phase proteins have been reported to increase in many infectious and inflammatory conditions such as trauma (Conner et al., 1988) and leishmaniasis (Martinez-Subiela et al., 2002). Thus, APP assays could be used as rapid screening tests for inflammation, providing better sensitivity when compared to other traditional markers (Solter et al., 1991). It has been stated that hormones, such as progesterone and estradiol, may modulate cytokine synthesis during pregnancy in human (Luppi, 2003). APP’s in pregnant dogs have been elucidated in various studies (Eckersall et al., 1993; Vanucchi et al.,2002; Kuri- bayashi et al., 2003). However, in neither of those studies all of the parameters were included in dogs along with each other (CRP, SAA, haptoglobin, ceruloplasmin and fibrinogen). C-reactive protein lev- els were investigated both by Eckersall et al. (1993) and Kuribay- ashi et al. (2003); fibrinogen, haptoglobin, ceruloplasmin seromucoid and glycoprotein by Vanucchi et al. (2002) whereas Concannon et al. (1996) had investigated fibrinogen and CRP. Van- ucchi et al. (2002) have focused on the difference between preg- nancy and diestrus in dogs. However, to the present authors’ knowledge the level of APP regarding different stages of the oestrus cycle in dogs have not been validated previously. The purpose of the present study was to evaluate the APPs profiles (CRP, SAA, hap- toglobin, ceruloplasmin and fibrinogen) in pregnant dogs as well as in bitches at various stages of the estrus cycle and to verify possible relationship(s) among the APPs profile and hormonal status. 2. Materials and methods 2.1. Animals Sixty (60) healthy bitches of various breeds ranging in age from 2 to 6 years were enrolled in this study. Blood samples were col- 0034-5288/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.rvsc.2008.09.001 * Corresponding author. Tel.: +90 256 2470700/173; fax: +90 256 2470720. E-mail address: paulutas@adu.edu.tr (P.A. Ulutas). Research in Veterinary Science 86 (2009) 373–376 Contents lists available at ScienceDirect Research in Veterinary Science journal homepage: www.elsevier.com/locate/rvsc