RESUMEN
Decreasing insulin sensitivity (IS) in peripheral tissues allows for partitioning nutrients towards the mammary gland. In dairy cows, extensive lipid mobilization and continued insulin resistance (IR) are typical for early lactation. Adiponectin, an adipokine, promotes IS. Supplementation with conjugated linoleic acids (CLA) in rodents and humans reduces fat mass whereby IR and hyperinsulinemia may occur. In dairy cows, CLA reduce milk fat, whereas body fat, serum free fatty acids and leptin are not affected. We aimed to investigate the effects of CLA supplementation on serum and adipose tissue (AT) adiponectin concentrations in dairy cows during the lactation driven and parity modulated changes of metabolism. High yielding cows (n=33) were allocated on day 1 post partum to either 100 g/day of a CLA mixture or a control fat supplement (CON) until day 182 post partum. Blood and subcutaneous (sc) AT (AT) biopsy samples were collected until day 252 post partum to measure adiponectin. Serum adiponectin decreased from day 21 pre partum reaching a nadir at calving and thereafter increased gradually. The distribution of adiponectin molecular weight forms was neither affected by time, parity nor treatment. Cows receiving CLA had decreased serum adiponectin concentrations whereby primiparous cows responded about 4 weeks earlier than multiparous cows. The time course of adiponectin concentrations in sc AT (corrected for residual blood) was similar to serum concentrations, without differences between CLA and CON. CLA supplementation attenuated the post partum increase of circulating adiponectin thus acting towards prolongation of peripartal IR and drain of nutrients towards the mammary gland.
Asunto(s)
Adiponectina/metabolismo , Tejido Adiposo/metabolismo , Suplementos Dietéticos , Lactancia/efectos de los fármacos , Lactancia/metabolismo , Ácidos Linoleicos Conjugados/administración & dosificación , Leche/metabolismo , Animales , Bovinos , Femenino , Leptina/metabolismo , Ácidos Linoleicos Conjugados/farmacología , Paridad/efectos de los fármacos , Periodo Posparto/efectos de los fármacos , EmbarazoRESUMEN
Adiponectin (AdipoQ) is an adipokine mainly secreted by white fatty tissue, playing a major role in energy homeostasis and insulin sensitivity. For cattle, AdipoQ data are largely limited to mRNA expression; to our knowledge, valid information about the AdipoQ protein in bovine tissues and body fluids is not available. Therefore, we have developed a monoclonal antibody against bovine AdipoQ. This study describes the preparation, application, and characterization of a monoclonal antibody for use in ELISA, Western blot, and histology. The antibody was developed by PEG fusion of the SP2/0 cell line with splenic B cells from AdipoQ immunized C57Bl/6 mice. Antibody-producing cells were identified by ELISA and specified by immunoblotting and immunostaining of bovine retroperitoneal adipose tissue. The novel antibody detects AdipoQ in histological samples, ELISA, and Western blots.
Asunto(s)
Adiponectina/inmunología , Anticuerpos Monoclonales de Origen Murino/química , Adiponectina/aislamiento & purificación , Adiponectina/metabolismo , Animales , Anticuerpos Monoclonales de Origen Murino/biosíntesis , Anticuerpos Monoclonales de Origen Murino/inmunología , Especificidad de Anticuerpos , Western Blotting , Bovinos , Ensayo de Inmunoadsorción Enzimática , Hibridomas , Inmunohistoquímica , Grasa Intraabdominal/metabolismo , Ratones , Ratones Endogámicos C57BLRESUMEN
The study was conducted to determine the baseline concentration of serum haptoglobin (Hp) in jennies during the breeding and nonbreeding season and to evaluate the effects of ovariectomy on serum Hp concentrations in jennies. Eighteen adult jennies were divided in three groups: nine jennies (OVA) were ovariectomized using laparoscopic surgery, six jennies (LAP) were exploratory examined by laparoscopic surgery, and three jennies were used as a control group. Blood samples were collected from the animals at Day -6, -2, -1, 0, 1, 2, 5, 8, 15, 22, 29 and 36 of surgery. Serum samples were analyzed by an ELISA specifically developed for determining equine Hp. The mean weekly Hp concentration ranged between 149.76 ± 7.55 and 178.94 ± 6.67 mg/L. The Hp concentrations of clinically healthy jennies revealed no significant variation among time, and there was no effect of reproductive season on Hp concentrations in jennies. Serum Hp concentration was elevated at the first day after operations in the OVA and LAP group. Five days after the operation, the Hp concentration reached the maximum in the LAP and OVA group (278.84 ± 34.22 and 359.88 ± 35.45 mg/L, respectively) and decreased at Day 8 after the operations. On Day 22, 29 and 32 after the operations, the concentration of Hp in LAP and OVA animals was close to its concentration in the control group. In conclusion, Hp is not related to reproductive status of jennies and it can be used as an indicator for cell and tissue damage after surgical operations.