Hyperglycemic and osmotic effects of dopamine and recombinant hormone CHH-B1 in the Pacific white shrimp Litopenaeus vannamei

Abstract

The effects of dopamine (DA) on crustacean hyperglycemic hormone (CHH) release and osmoregulation were investigated in the white shrimp Litopenaeus vannamei. Application of 2 μg of the recombinant CHH-B1_His hormone or 2 × 10⁻⁶ mol L⁻¹ of DA to intact shrimp caused an increase in the hemolymph glucose levels 1 h post-injection, suggesting that DA might stimulate hyperglycemia through CHH release from the sinus glands. This assumption was supported by similar experiments using bilaterally eyestalk-ablated shrimp. Additionally, rCHH-B1_His restored the osmoregulatory capacity (OC) of shrimp under hyperosmotic conditions to basal values 2 h post-injection, whereas DA led to an OC decrease in shrimp at all sampling times. These neuroendocrine factors may be involved in the control of metabolism and osmoregulation in L. vannamei and could be important for its adaptation to different environmental conditions.

Keywords:

• Osmoregulatory capacity
• dopamine
• recombinant protein
• crustacean hyperglycemic hormone
• Litopenaeus vannamei

Acknowledgments

We thank Dr. John van der Meer for his helpful suggestions in polishing the English in the manuscript. We appreciate Jennifer Mancera Flores for her technical assistance.