Purinergic signalling in endocrine organs

Abstract

There is widespread involvement of purinergic signalling in endocrine biology. Pituitary cells express P1, P2X and P2Y receptor subtypes to mediate hormone release. Adenosine 5′-triphosphate (ATP) regulates insulin release in the pancreas and is involved in the secretion of thyroid hormones. ATP plays a major role in the synthesis, storage and release of catecholamines from the adrenal gland. In the ovary purinoceptors mediate gonadotrophin-induced progesterone secretion, while in the testes, both Sertoli and Leydig cells express purinoceptors that mediate secretion of oestradiol and testosterone, respectively. ATP released as a cotransmitter with noradrenaline is involved in activities of the pineal gland and in the neuroendocrine control of the thymus. In the hypothalamus, ATP and adenosine stimulate or modulate the release of luteinising hormone-releasing hormone, as well as arginine-vasopressin and oxytocin. Functionally active P2X and P2Y receptors have been identified on human placental syncytiotrophoblast cells and on neuroendocrine cells in the lung, skin, prostate and intestine. Adipocytes have been recognised recently to have endocrine function involving purinoceptors.

Extracellular ATP and other nucleotides—ubiquitous triggers of intercellular messenger release

“…Physiological mechanisms controlled by extracellular nucleotides, and by ATP in particular, include neurotransmission and neuromodulation [4], glial and glial-neuron interactions [5], the development of the nervous system [6], pain [7], control of hormone secretion [8], sensory transmission [9], the function of a variety of organ systems such as the special senses [10], kidney and urinary tract [11,12], liver [13], the cardiovascular system [14,15], the immune system [16,17], the musculoskeletal system [18,19], the airways [20], the gastrointestinal system [21], or pancreatic and salivary gland epithelia [22]. Signaling via extracellular nucleotides is even more prominent in multiple pathological conditions, including neuropathic pain, a considerable number of disorders of the central nervous system, such as trauma, cerebral ischemia, multiple sclerosis, Parkinson's disease, or Alzheimer's disease [23], and diseases of essentially every peripheral organ system, including cardiovascular disorders, cancer, and inflammation [13,[24][25][26][27].…”

“…Since then, the mechanisms of nucleotide-mediated regulation of insulin release have been intensively studied with partially conflicting results and have recently been reviewed in detail [8,[263][264][265]. Notably, the impact of nucleotides and the cellular mechanisms leading to insulin release vary between species.…”

Inseparable tandem: evolution chooses ATP and Ca2+to control life, death and cellular signalling

“…In many cells, these receptors are coupled, via several G proteins, to phospholipase C that produces InsP 3 and initiates Ca 2þ release from the endoplasmic reticulum. The ATP-induced Ca 2þ signalling mediated through the metabotropic route seems to be almost universal in non-excitable cells, being present in immune cells [236], in neuroglia [237], in kidney [238], in cells of urinary tract [239], in skin, bone and cartilages [240], in endocrine glands [241], etc. The P2Y receptors and their downstream Ca 2þ signalling can be activated not only by ATP, but also by other nucleotides including ADP, UTP, UDP and UDP-glucose [242,243].…”

Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation

“…2). ATP and ADP (adenosine tri-and diphosphate) are intermediates secreted into the extracellular space by a cell exposed to stimuli (pH, UV, reactive oxygen species; Burnstock, 2014), to communicate with adjacent cells. Here, these messages could be taken up by the enzyme ectonucleoside triphosphate diphosphohydrolase (ENTPDase) and bound to purine receptors in the membrane of a neighboring cell.…”