Total ghrelin levels in WT and GOAT-KO mice on a normal or leptin-deficient ob/ob background.

<p>GOAT-KO and GOAT-ob/ob mice with a complete lack of acyl ghrelin have increased plasma concentration of total (desacyl) ghrelin. Total ghrelin levels are lower in both ob/ob as well as GOAT-ob/ob mice, compared to lean WT controls or GOAT-KO mice on chow diet. ^# P<0.05 versus dWT; ** P<0.001 versus GOAT-KO; ^$$ P<0.001 versus ob/ob; n = 4–7.</p

GOAT ablation does not improve glucose homeostasis in mice on a leptin-deficient ob/ob background.

<p>a) Fasting insulin levels in 4-month-old chow-fed WT, GOAT-KO, ob/ob mutant and GOAT-ob/ob mice. b) Glucose tolerance tests (b left panel; 1 g glucose/kg body weight) in chow-fed mice revealed no improvement in glucose tolerance by GOAT ablation. Insulin tolerance tests in mice fed with MCT diet (b right panel; 0.75 U insulin/kg body weight) suggested severe insulin resistance in both GOAT-ob/ob and ob/ob mutant mice, and a normal insulin sensitivity in GOAT-KO and dWT mice. (n = 6–10).</p

Body weight, fat mass and fat free mass in male mice lacking GOAT on a leptin-deficient ob/ob background.

<p>GOAT-ob/ob mice fed standard chow diet display no differences in body weight (a), fat mass (b), or fat free mass (c), compared to ob/ob littermates. However, both leptin-deficient mutants differ significantly in their body adiposity from GOAT-KO and dWT mice, respectively. ** P<0.01 (1-way ANOVA); (n = 5–7).</p

Genotyping conditions.

<p>Fwd, forward; Rev, reverse; bp, base pairs; Mboat4, Membrane bound-O-acyl transferase 4; ob, obese.</p

Metabolic phenotypes of ob/ob mutants and GOAT-ob/ob double mutants after exposure to medium-chain triglyceride (MCT) enriched diet.

<p>Leptin-deficient ob/ob and GOAT-ob/ob double mutant mice were fed MCT diet for 8 weeks. No differences were observed for body weight (a) and fat mass or fat free mass (b). Further, indirect calorimetry after 7 weeks of MCT diet exposure revealed no differences in food intake (c), energy expenditure (d), respiratory quotients (e) or locomotor activity (f, P = 0.16). (n = 4–7).</p

Stable blood glucose levels after partial or complete loss of body fat.

<p>Even after a partial (2% fat mass; A&B) or complete (0% fat mass; C&D) loss of body fat, calorie-restricted ghrelin-loss-of-function mice and their WT controls were able to maintain stable blood glucose levels. Values depict means ± SEMs from groups of 8 male GOAT WT, 5 female GOAT WT, 9 male GOAT KO, 8 female GOAT KO, 10 male Ghr-GHSR dWT, 20 female Ghr-GHSR dWT, 19 male Ghr KO, 18 female Ghr KO, 7 male GHSR KO, 19 female GHSR KO, 16 male Ghr-GHSR dKO and 7 female Ghr-GHSR dKO mice.</p

Number, age, initial vs. final body morphometry, and final acyl/desacyl-ghrelin, insulin and IGF-1 plasma levels of loss-of function ghrelin or their respective WT control mice after CR.

<p>Data are shown as Mean ± SEM. “n.d.” indicates not detectable;</p><p>*p<0.05,</p><p>**p<0.001 vs. GOAT WT;</p>†<p>p<0.05,</p>††<p>p<0.01 vs. Ghrelin-GHSR WT;</p>§<p>Number of mice removed from studies with two consecutive hypoglycemic events of blood glucose levels ≤50 mg/dL;</p>a<p>n = 4;</p>b<p>n = 3;</p>c<p>n = 4.</p

Change of body weight and fat mass in WT and ghrelin-loss-of-function mice after chronic CR.

<p>Male (A,B) and female (C,D) wildtype (WT) and GOAT, Ghrelin (Ghr), GHSR, or Ghr-GHSR dKO mice were subjected to chronic CR (40% of <i>ad libitum</i> calories), and changes in body weight (A,C) and fat mass (B,D) were recorded. Values are shown for each individual animal. Mice were taken out of the CR regiment when fat mass dropped to 0% for 2 consecutive days, or when mice became severely hypoglycemic. Lines depict body weight and fat mass curves for individual animals from groups of 8 male GOAT WT, 5 female GOAT WT, 9 male GOAT KO, 8 female GOAT KO, 10 male Ghr-GHSR dWT, 20 female Ghr-GHSR dWT, 19 male Ghr KO, 18 female Ghr KO, 7 male GHSR KO, 19 female GHSR KO, 16 male Ghr-GHSR dKO and 7 female Ghr-GHSR dKO mice.</p