Do pancreatic islet A cells have receptors that receive insulin?

Pancreatic islet A cells secrete glucagon, glucagon and insulin are orange anti-effects, and insulin can inhibit the secretion of glucagon, so pancreatic islet A cells must have insulin receptors.

The following experiment found that there are insulin receptors on the A cells of pancreatic islets, and if these receptors are destroyed, glucagon secretion will increase, and hyperglycemia will occur. This fact shows that insulin has an inhibitory effect on glucagon secretion by A cells.

Yes. Pancreatic islet A cells can also act as tissue cells, and insulin can also act on pancreatic islet A cells to promote the absorption and utilization of glucose by pancreatic islet A cells.

At the same time, during blood sugar regulation, insulin acts on pancreatic islet A cells and inhibits the secretion of glucagon.

Insulin receptors are mainly liver cells, muscle cells, and adipose tissue cells, which should not be present.

Answer]: B insulin is secreted by pancreatic B cells (cells), glucagon is secreted by A cells (cells), somatostatin is secreted by pancreatic D cells, and active intestinal peptides are present in the central nervous system and enteric nervous system, and can also be secreted by pancreatic D cells. Pancreatic polypeptides are secreted by PP cells in the pancreas.

Therefore, the answer to this question is b.

Answer]: B insulin is secreted by pancreatic B cells, somatostatin is secreted by pancreatic islet orange D cells, vasoactive intestinal peptide is secreted by pancreatic D1 cells, and pancreatic polyssonopeptide is secreted by pancreatic islet PP cells.

Answer] :d insulin needs to bind to the insulin receptor on the surface of the target cell membrane to exert biological activity, which is mainly distributed in brain schick cells, sexual segment wide glandular cells, red blood cells and blood answering tube endothelial cells, which is a tetramer composed of two subunits, has a high affinity for insulin, has tyrosine-specific protein kinase activity, and the second messenger is not camp. The correct answer to this question is d.

b.Growth factor receptors.

c.Ion channel bond trapping receptors.

d.Intracellular receptors.

Correct answer: Manuscript wide reading Qiaozheng GPR

The somatic cells of the selected C human contain all the genes of the person, but they are expressed differently in different cells, which is called selective expression.

The genes of eukaryotes are composed of non-coding and coding regions, the coding regions are composed of introns and exons, only exons can translate proteins, human pancreatic islet cells can produce insulin because the insulin gene is on the exons, and other genes are on the non-coding region or introns and are not expressed.

【Answer】c

Answer analysis] Question analysis: Each somatic cell contains all the genes of the organism, but not every gene can be expressed, pancreatic islet cells express insulin genes, while hemoglobin genes cannot be expressed.

Test Place: Structure and function of genes.

According to their staining and morphological characteristics, human pancreatic islet cells are mainly divided into islet A cells, B cells, D cells and PP cells. A-cells make up about 20% of pancreatic islet cells. Pancreatic islet A cells secrete glucagon.

The receptor for insulin is the insulin receptor: a tetramer consisting of two subunits and two subunits linked by disulfide bonds. Two subunits are located on the outer side of the cytoplasmic membrane, on which there are binding sites for insulin; The two subunits are transmembrane proteins that play a role in signal transduction.

In the absence of insulin binding, the receptor's tyrosine protein kinase is inactive.

When insulin binds to the subunit of the receptor and changes the configuration of the subunit, tyrosine protein kinase is activated, which catalyzes two reactions to phosphorylation of tyrosine residues at subunit specific sites in the tetrameric complex, a process called autophosphorylation; Phosphorylation of more than a dozen important tyrosine residues on the insulin receptor substrate (IRSS) binds to and activates downstream effectors.