Chapter 34: Nitrogen: Metabolic Integration
A 33-year-old female patient presented complaining of a tender abdomen and fever. Examination revealed marked abdominal distension, acidosis, and leukocytosis. Laparoscopy revealed that large parts of the small intestine were necrotic and as a consequence, the entire ileum and the proximal portion of her colon were resected. Due to the resulting loss of a particular set of enteroendocrine cells, this patient is most likely to experience which of the following?
A. increased fatty acid content of the feces
B. increased gastric acid secretion
C. increased hypoglycemia during periods of fasting
D. loss of cholecystokinin-induced release of protein tyrosine tyrosine (PYY)
E. loss of ghrelin-mediated appetite induction
Answer D: PYY is produced by, and secreted from, intestinal enteroendocrine L-cells of the ileum and colon. Within the gastrointestinal tract, the highest detectable levels of PYY are found in the rectum with low levels found in the duodenum and jejunum. Within the central nervous system (CNS), PYY is detectable in the hypothalamus, medulla, pons, and spinal cord. The signals associated with the response of the proximal gut to food intake that lead to PYY release are the result of CCK and gastrin activity.
A 14-year-old boy presents with weight loss and diarrhea. His tongue becomes sore and blistery after eating oatmeal or rye bread, which leads to the diagnosis of celiac disease. The boy and his parents are advised to be sensitive to symptoms of malabsorption of calcium. Which of the following would be a most likely symptom of which the parents should be aware?
D. methylmalonic acidemia
Answer B: In patients with celiac disease, the protein gluten, which is found in bread, oats, and many other foods containing wheat, barley, or rye, triggers an autoimmune response that causes damage to the small intestine, leading to widespread manifestations of malabsorption. Calcium is difficult to absorb, so patients frequently experience symptoms of hypocalcemia such as muscle cramping, tetanic contractions, numbness, and tingling sensations. For sensory and motor nerves, calcium is a critical second messenger involved in normal cell function, neural transmission, and cell membrane stability. The nerves respond to a lack of calcium with hyperexcitability.
As a physician on a mission to treat patients in sub-Saharan Africa you encounter numerous children with a common cluster of signs and symptoms. These ...