Serum amyloid A protein (SAA), haptoglobin (Hp) and selected hematological and biochemical parameters in wild mares before and after parturition

Serum Amyloid A as a Promising Biomarker in Domestic Animals’ Reproduction: Current Knowledge and Future Perspective

Simple Summary

Acute phase proteins (APPs) are useful markers which can be evaluated in animals to assess health status and characterize inflammation, infection, and trauma. Among APPs, serum amyloid A (SAA) has been widely investigated in pets and food-producing species as a possible biomarker of inflammatory and infective conditions, especially in the field of animal reproduction. The aims of this paper are to review the literature available on the use of SAA for the diagnosis and monitoring of inflammatory reproductive disease in animals, critically appraising the usefulness of such marker and summarizing the current state of knowledge.

Abstract

The investigation of acute phase proteins in veterinary medicine has opened the doors towards the identification and use of new markers for a timely assessment of health status in both companion and food-producing animals. The aim of this paper is to review the literature available on the use of serum amyloid A (SAA), an acute phase protein, for the diagnosis and monitoring of reproductive disorders in animals. This review critically appraises the usefulness of such marker in clinical practice and summarizes the current state of knowledge. Recent advances in the diagnosis and monitoring of reproductive diseases are presented, highlighting where SAA evaluation may enhance early diagnostic tools for dogs, cats, cattle, and equines.

Circulating endocrine, metabolic, and haematologic indices during the peripartum period of Darehshori mares

The characteristics associated with equine peripartum period are different from those of other periods. Information concerning the values and dynamic changes of circulating peripartum endocrine, metabolic, and haematologic indices may improve the understanding of the whole body haemostatic patterns which lead to parturition, lactogenesis, and estrus in the horse. The present study aimed to evaluate these changes around parturition in Darehshori breed. For this purpose, blood sampling was performed on six clinically healthy Darehshori mares (10 years old) about one week prior to parturition, three days following parturition, at the beginning of estrus, and one week after estrus. Circula­ting values ​​of glucose, estrogen, progesterone, cortisol, T3, T4, TG, cholesterol, HDL, LDL, VLDL, RBC, HGB, HCT, MCV, MCH, MCHC, WBC, neutrophil, lymphocyte, and PLT were assessed in all samples. Progesterone concentrations were minimum before parturition and increased significantly one week after foaling heat (P=0.035). Cortisol level was significantly higher during foaling heat compared with other periods (P=0.029). T4 levels significantly increased from pre- to post-partum periods (P=0.001), but T3 showed increased and decreased values during the study period. All serum lipid profile parameters were significantly reduced from pre to postpartum period (P<0.05). Haematological parameters in mares significantly changed during the peripartum period (P<0.05). Based on the results, the metabolic, haematological, endocrinological, and stress indices in Darehshori mares were found to change around parturition and the first estrus. These changes were largely dependent on hormonal mechanisms related to pregnancy and parturition occurring in normal mares.

Interrelationship between reproductive hormones and acute phase proteins during estrous cycle and pregnancy in Spanish purebred broodmares

In some species, female steroid hormones modify the profile of acute phase proteins (APPs) during the estrous cycle and pregnancy, according to the ovulation, embryonic implantation and placental development; however, nowadays there's no experimental evidence for equine species. Objectives of this study were: to compare the serum amyloid A (SAA), haptoglobin (Hp) and C-reactive protein (CRP) concentrations between cyclic and pregnant mares, and to analyze the influence of estradiol-17β (E2) during estrous cycle or estrone sulfate (E1) during pregnancy, and progesterone (P4) on these proteins to assess their potential role to identify the cyclicity or pregnancy in Spanish mares. Blood samples were taken from 20 Purebred Spanish mares on the day of ovulation (day 0), on days +5 and +16 post-ovulation, and then, monthly during the whole pregnancy. SAA, Hp and CRP did not change between day 0, +5 and +16 post-ovulation days. P4 concentrations were significantly higher on day +16 than on days +5 and 0; and E2 concentrations were significantly higher on day 0 than day +5. On the other hand, pregnancy was characterized by a progressive increase in the Hp, variable modifications of E1 and P4 concentrations, without changes in SAA and CRP. The absence of significant differences in the APPs between days 0, +5 and +16, suggested that these proteins cannot be used as biomarkers of diagnosis of heat or pregnancy in Spanish mares, at least early, since the Hp later increases during the gestation. Nevertheless, it is possible to use them for comparative purposes with other equine breeds, as supervisor instrument of health status in breeding females as diagnostic tools to monitor pregnancy's development and/or subclinical reproductive inflammations, that could lead to the early embryonic death.