Genetics, Physiology, and Health Research to Improve Catfish Production
Location: Catfish Genetics Research
Title: GH and IGF-I induction by passive immunization of rainbow trout Oncorhynchus mykiss Walbaum using a somatostatin 14 antibody
| Lakeh, Amir - |
| Farahmand, Hamid - |
| Mirvaghefi, Alireza - |
| Kloas, Werner - |
| Wuertz, Sven - |
Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 5, 2011
Publication Date: February 26, 2011
Citation: Lakeh, A.B., Farahmand, H., Mirvaghefi, A., Kloas, W., Peterson, B.C., Wuertz, S. 2011. GH and IGF-I induction by passive immunization of rainbow trout Oncorhynchus mykiss Walbaum using a somatostatin 14 antibody. Aquaculture. 316:99-103.
Interpretive Summary: Somatostatin-14 is a hormone that negatively regulates growth hormone (GH) production in mammals and fish. We made antibodies to SS-14 using the egg yolks from laying hens. Maximum antibody titers were observed at day 40 after injection. Rainbow trout were injected with extracted anti-SS-14 antibodies at a dilution of 1:25 and plasma GH concentrations increased after 30 min and reached a maximum after 120 min. Plasma levels of insulin like growth factor I (IGF-I), a hormone that regulates growth, were increased at 30, 120, and 240 min and continued to be increased after 1 day of injection. Injecting fish with anti-SS-14 antibodies demonstrated an up regulation of plasma GH and IGF-I. The increase in levels of these hormones known to be involved in growth regulation, suggests anti-SS-14 antibodies produced from chickens may have application in growth promoting growth in aquaculture species.
Inhibition of the growth axis by somatostatin was studied in juvenile rainbow trout using passive immunization with a previously isolated somatostatin antibody (antiSS-14). Upon subcutaneously injection of laying hens (Gallus domesticus) with conjugated somatostatin-14 (SS-14), the antiSS-14 was isolated from egg yolk. Isolation of immunoglobulin was carried out at 40 d, revealing maximum IgY titre (IgY) at 3.22 ± 0.08 compared to control (0.1 ± 0.04) and highest total protein of 183 ± 2 mg ml-1 compared to the control (85 ± 3 mg ml-1). Passive immunization with extracted IgY at a dilution of 1:25 increased GH plasma concentrations after 30 min, reaching a maximum at 35 ± 7 ng ml-1 after 120 min. GH remained elevated for over a day, returning to baseline at 2 d. At 1:100, GH increased and returned to normal after 2d. . At 1:25, IGF-I plasma concentrations were increased at 30 min (277± 74 ng ml-1, p<0.05), 120 min (212 ± 77 ng ml-1,p>0.05), 240 min (359 ± 172 ng ml-1, p<0.05) and 1 d (259 ±117 ng ml-1, p<0.05) compared to the control (n=7, Tukey Test), returning to baseline levels after 2 d (145 ± 45 ng ml-1). In the 1:100 treatment group, slightly elevated GH did not induce IGF-I, which fluctuated between 13 8± 15 ng ml-1 and 167 ± 35 ng ml-1 (n =7, p>0.05) compared to the control fish, ranging from 131 ± 10 ng ml-1 to 148 ± 6 ng ml-1. Passive immunization thus demonstrates up regulation of plasma GH and IGF-I, suggesting the blockage of SS-14 mediated growth inhibition. The simplicity of antiSS-14 production in chicken eggs applied even suggests a potential use for growth promotion in aquaculture.